Media playback is unsupported on your device Media caption East Aleppo resident says he would rather die than return to government controlled Syria 
 
 Syrian government forces have captured more than a third of rebel-held territory in eastern Aleppo. 
 
 The advance, after heavy bombing from the air, is a major blow for the armed opponents of President Bashar al-Assad. 
 
 State TV said government troops were dismantling mines and explosives and continuing their advance. 
 
 Thousands of civilians have fled the besieged districts after a weekend of heavy fighting. Hundreds of families have been displaced. 
 
 What are the latest developments? 
 
 Rebel fighters have been driven out of more neighbourhoods of their long-held enclave in eastern Aleppo, as Syrian government forces continue to advance. 
 
 After further fighting on Monday, the rebels are reported to have lost all of the northern neighbourhoods they controlled before the weekend, leaving them with under two-thirds of the territory they had in the city. 
 
 Two rebel officials told Reuters their forces had withdrawn to a more defendable front line after government advances risked splitting the rebel-held area in two. 
 
 Syrian government troops now control the section of east Aleppo north of the Sakhour highway, according to monitors. 
 
 Russia's defence ministry says Syrian government troops have captured 12 districts, or 40% of the territory, from the rebels. 
 
 It says that more than 100 rebels have laid down their arms and left the city. 
 
 Aerial bombardment of rebel-held areas was continuing on Monday, according to the UK-based Syrian Observatory for Human Rights. 
 
 The Syrian army and its allies launched a major offensive to retake control of Aleppo in September. 
 
 What has happened to residents? 
 
 Image copyright The Rumaf via AP Image caption This woman and her young child were among those fleeing to the Sheikh Maqsoud area 
 
 Thousands of residents of east Aleppo have fled to areas controlled by government forces and Kurdish groups since the fighting intensified on Saturday. 
 
 The Syrian Observatory for Human Rights said as many as 10,000 residents fled to government-controlled western areas and a Kurdish-run northern district. 
 
 State media showed men, women and children being transported to government-held areas on green buses. 
 
 Kurdish groups who control the Sheikh Maqsoud area of Aleppo provided images showing people fleeing the rebel-held neighbourhoods into a Kurdish-controlled district. 
 
 Media playback is unsupported on your device Media caption UNHCR spokesperson describes on Radio 4's Today the severity of the humanitarian crisis in Aleppo 
 
 A spokesman for the Syrian Kurdish PYD party told Reuters that 6,000-10,000 people had fled into the district. 
 
 Scott Craig, the spokesperson for the United Nations High Commissioner for Refugees in Syria, told the BBC that there were 250,000 people in need of assistance in eastern Aleppo, 100,000 of them children. Food supplies were gone, he said. 
 
 "The situation on the ground in eastern Aleppo is almost beyond the imagination of those of us who are not there," Mr Craig said. 
 
 Warning of a humanitarian disaster, a volunteer rescue service known as the White Helmets said it had run out of fuel reserves needed to reach people caught in the onslaught. 
 
 On Sunday, seven-year-old Bana Alabed, who has gathered thousands of Twitter followers with her tweets from Aleppo, said her home in the east of the city had been bombed. 
 
 Image copyright @AlabedBana 
 
 On Monday morning, her account tweeted: 
 
 "Under heavy bombardments now. In between death and life now, please keep praying for us." 
 
 Media playback is unsupported on your device Media caption Meet Bana Alabed, the seven-year-old girl who has been tweeting from war-torn Aleppo 
 
 Last week the United Nations' humanitarian chief, Stephen O'Brien, said that hundreds of civilians had been killed or injured since the bombardment of eastern Aleppo resumed six days earlier. 
 
 He also highlighted deaths and injuries resulting from mortar and rocket attacks from rebel-held areas into western Aleppo. 
 
 Why has this happened now - and why does it matter? 
 
 This advance follows two weeks of relentless aerial bombardment, as the government and its allies renewed their assault on the rebel-held portion of Aleppo. 
 
 It followed a three-week pause in the Russian and Syrian bombing of the area, which ended on 15 November. 
 
 There are no fully-functioning hospitals left in the rebel-held territory and food ran out earlier in November. 
 
 Since the start of this month's offensive, pro-government forces have conducted 2,000 airstrikes, bombing the city with some 7,000 artillery rounds as well as ballistic missiles, cluster munitions and chlorine gas, according to the White Helmets rescue group. The BBC has not been able to verify these figures. 
 
 Media playback is unsupported on your device Media caption Aleppo: Key battleground in Syria's civil war 
 
 UN envoy Staffan de Mistura estimated last month that there were 8,000 rebel fighters in eastern Aleppo. 
 
 Retaking the whole of Aleppo, Syria's second largest city, is a key aim of the Syrian government. The east of Aleppo has been held by rebel factions opposed to President Bashar al-Assad for the past four years. 
 
 Government forces have taken more and more territory from them since Russia intervened to back its ally, President Assad, in September 2015. 
 
 Iranian-backed militias and Russian air strikes have helped Syrian government forces to break the deadlock. 
 
 Russia says its air force is active in other parts of the country, but has not operated over Aleppo since the pause. 
 
 Analysis - by Jonathan Marcus, BBC diplomatic correspondent 
 
 The tide is clearly turning in Aleppo in favour of the Assad regime - raising serious questions about the ability of the disparate rebel groupings to maintain a significant area of control in northern Syria. 
 
 The recapture of the city would be an important symbolic achievement for President Assad - underlining the fact that despite all the calls for his departure, Russian and Iranian support has been able not just to maintain him in power, but has enabled the regime to go onto the offensive. 
 
 Indeed, external military support has been crucial. After years of gruelling attritional combat the regular Syrian army, despite new arms supplies from Moscow, is a shadow of its former self. 
 
 The battle for Aleppo has depended upon air power and a variety of pro-Iranian militias, including Hezbollah fighters on the ground. 
 
 This has cemented Iran's key role in the conflict, which may have consequences in the future. ||||| Media caption The BBC's Ian Pannell travels with cheering rebels in Aleppo. His report contains unverified graphic images of the victims of Syria's conflict 
 
 Syrian rebels in Aleppo have begun stockpiling ammunition and medical supplies as government forces prepare outside the city for a major battle. 
 
 Artillery and helicopter gunships have resumed attacking rebel targets and 14 people have been killed, activists say. 
 
 Troops and tanks are said to be ringing the city and reinforcements are reportedly on their way to join them. 
 
 In Damascus, activists said the army had pounded the capital's last rebel-held areas and 20 civilians had died. 
 
 Five children and four women were killed, according to London-based pro-opposition group Syrian Observatory for Human Rights, when shells hit the Yalda area. Helicopters also attacked the nearby district of Hajar al-Aswad. 
 
 The government has said its forces are trying to dislodge the "remnants of mercenary terrorist groups". 
 
 At the scene It is almost inconceivable that President Assad could allow his government to lose control of the city, so it is reasonable to expect that they are going to throw everything they possibly can at the city. And that is what they are preparing for here. One of the neighbourhoods is appealing for more blood supplies. We are hearing reports of hundreds, possibly thousands of families leaving some districts. Everybody is bracing themselves for an intensive campaign. The way it has worked in other cities is that there is an intensive bombardment by artillery and mortars, and then when it starts to go calm, tanks begin to roll in. This is a very congested heavily populated area, so it will be bloody. Rebels surprise regime in Aleppo 
 
 Checkpoints and snipers 
 
 In Syria's commercial hub of Aleppo, rebels have set up checkpoints and sniper positions and claim to be in control of half of the city. 
 
 A Syrian security source was quoted by AFP news agency as saying that special forces had begun arriving on the edges of Aleppo in readiness for a "generalised counter-offensive on Friday or Saturday". 
 
 A similar account has emerged from the Syrian Observatory for Human Rights, which talks of reinforcements arriving from the main Damascus to Aleppo road to the south. 
 
 Columns of troops and tanks are also thought to be travelling from the city of Hama, and from the border posts with Turkey in Idlib province. 
 
 Aleppo is the country's commercial capital, and key to the battle to control the north of the country. 
 
 Street battles have been reported throughout the city for days, as rebels try to hold on to neighbourhoods captured in an offensive that began at the weekend. 
 
 Although it was relatively quiet on Thursday, activists said artillery fire could be heard in the Salah al-Din neighbourhood in the southwest of the city and clashes in Tariq al-Bab in the east had led to two rebels being killed. 
 
 Foreign journalists operate under heavy restrictions in Syria so claims made by either side are difficult to verify. 
 
 The BBC's Ian Pannell near the city says thousands of people are leaving as fears grow that an intense battle is looming. 
 
 He says the rebels are reinforcing their ranks with more fighters, medical supplies, and ammunition such as Kalashnikov rifles. 
 
 Talal al-Mayhani, an activist with connections in the rebel movement in Aleppo, said the battle for the city was likely to play out in a similar way to an earlier battle in the capital Damascus, when rebels took control of large parts of the city before being forced to withdraw in the face of a government offensive. 
 
 Reporter Laurent Van der Stockt from French newspaper Le Monde told the BBC that Free Syrian Army (FSA) commanders in Aleppo were full of confidence but were lacking weapons. 
 
 "A commander told me this morning they attacked a convoy and destroyed 10 armoured vehicles." 
 
 Luke Harding of the Guardian newspaper, 50km (30mi) west of Aleppo, told the BBC that much of the rest of Aleppo province was in rebel hands but it was an exaggeration to say they were in control of half of the city. 
 
 "It's true they're in the southern part of the city and the northeast. Tactically, they're doing guerrilla-style attacks and they can melt away quite quickly." 
 
 In Damascus, where government forces have largely repelled a sustained assault by rebels, state TV reported more clashes in the southern district of Qadam. 
 
 The report showed army troops firing intensively as they moved into heavily damaged streets. 
 
 The violence also spread to the Yarmouk Palestinian refugee camp, where activists said street battles had taken place between rebels and soldiers. 
 
 More than 16,000 people have been killed in Syria since the start of anti-regime protests in March 2011. 
 
 Repeated diplomatic attempts to stop the violence have foundered, with the UN Security Council bitterly divided. 
 
 Thousands of refugees have already sought shelter in Turkey, Lebanon, Jordan and Iraq. 
 
 And conditions throughout the country have worsened as the fighting has spread and intensified in the two main cities in recent weeks. ||||| Syrian troops fired tank shells and artillery Sunday at neighborhoods in Aleppo as rebels tried to repel a government ground assault against their positions in Syria's largest city, activists said. 
 
 In this photograph made on Friday, July 27, 2012, Syrian rebels arrest a man who they said was a government informant in Aleppo, Syria. (AP Photo/Alberto Prieto) (Associated Press) 
 
 The bombardment was part of a government counter-offensive to retake control of districts that had fallen into rebel hands last week at the beginning of their bid to capture Aleppo, the nation's commercial hub. 
 
 Activists said the shelling was most intense in the southwestern neighborhoods of Salaheddine and parts of Saif al-Dawla, some of the first areas seized by the rebels when they started the push last week after being routed in a similar attack against the capital Damascus. 
 
 The battle for control of Aleppo, once a bastion of support for President Bashar Assad's regime, is critical for both the regime and the opposition. Its fall would be a major blow to the regime's morale and a realization of the opposition's crucial and strategic goal to establish a stronghold in northern Syria. 
 
 The government pledged to continue fighting and said security agents were hunting down armed groups in several areas of Aleppo including Saleheddine, inflicting heavy losses upon the "terrorists" _ the term authorities use to describe Syrian rebels. 
 
 SANA quoted an Aleppo official as saying that troops would continue until the city is "purged" of armed groups and peace and tranquility is restored to its residents. 
 
 "We are seeing some of the heaviest bombardment today, but the rebels are still holding up well," said Aleppo-based activist Mohammed Saeed. "No ground troops have been able to enter. They are shelling from outside." He said rebels were fighting back against the attackers. 
 
 He said around 200 fighters entered the city Sunday to join about 1,000 fighters who had poured into the city in the past few days to take on the Syrian army, which had been massing forces around the city ahead of the bombardment. 
 
 He also said rebels have received "a new batch of weapons and ammunition," but declined to say from where. 
 
 The Britain-based Syrian Observatory for Human Rights also reported heavy fighting and explosions in Aleppo Sunday. It reported intense clashes in the Bab al-Hadeed, al-Zahraa and al-Arqoub neighborhoods. 
 
 The international community has raised an outcry about a possible massacre in this city of 3 million but acknowledged there was little they could do to stop the bloodshed. The foreign minister of Russia, a powerful ally of Syria, said it was "simply unrealistic" for Damascus to cede control of Aleppo. 
 
 The rebels are estimated to control between a third and a half of the neighborhoods in this sprawling city, especially a cluster in the northeast around Sakhour neighborhood and in the southwest. 
 
 They began their attempt to wrest this key city from the government's control a week ago. About 162 people have been killed, mostly civilians, according to the Observatory. Some 19,000 people have been killed since the uprising began in March 2011, the group says. ||||| Aleppo, Syria (CNN) Syrian government troops now control most of the neighborhoods in the old city of Aleppo after days of fierce fighting against rebel forces, with only small pockets remaining in opposition hands. 
 
 Overall, the rebels hold only about a quarter of war-ravaged eastern Aleppo, residents and activists inside the city told CNN on Wednesday. 
 
 As of Wednesday morning, the Syrian army had retaken the key area of al-Shaar and most of the neighborhoods in the old city, including Agheour, al-Farafrah and Bab al-Hadeed, they said. 
 
 Activists with the Aleppo Media Center said some parts "fell by default because the rebel fighters withdrew." 
 
 As the situation in Aleppo changes rapidly, CNN will update the map with information from sources on the ground. 
 
 Other neighborhoods had already fallen in recent days as government forces, backed by a brutal aerial bombardment, pushed into areas held by the rebels for more than four years. 
 
 Meanwhile, many civilians remain trapped in the shrinking rebel-held portion of the devastated city. Food, fuel and medical supplies are almost exhausted with no safe route out. 
 
 One activist in eastern Aleppo told CNN as many as 200,000 people -- including rebels and their families -- were crammed into 10 rebel-held neighborhoods, some having fled from other areas under fire. 
 
 JUST WATCHED CNN on the ground in war-ravaged Aleppo Replay More Videos ... MUST WATCH CNN on the ground in war-ravaged Aleppo 03:10 
 
 He described the situation as "apocalyptic," saying the few hospitals still operating were packed with injured civilians and resembled "slaughterhouses," with no medical supplies or proper facilities. 
 
 Dozens of people have been killed daily in the strikes and crossfire between the regime and rebels since the Syrian forces began their push into eastern Aleppo on November 26, activist groups said. 
 
 Though their territory is shrinking, rebels are also inflicting losses. 
 
 At least 12 civilians were killed and 64 others wounded Wednesday in rebel shelling of government-held neighborhoods in western Aleppo, Syrian state media reported. 
 
 The report said rebels fired dozens of rockets on residential neighborhoods and that the death toll was expected to rise. 
 
 Fleeing Syrians line up at crossing 
 
 Hundreds of exhausted Syrians pushing carts and carrying suitcases and plastic bags filled with their life's possessions waited Wednesday morning for buses to take them from eastern to western Aleppo. 
 
 Some who spoke to CNN in the Agheour area, by the main Maysaloon crossing, described appalling conditions -- days gripped by hunger and fear of airstrikes. 
 
 Syrians are fleeing old town neighborhoods of eastern Aleppo after the Syrian army's gains. 
 
 to the A CNN crew saw 25 people cross on foot in 20 minutes, with more coming all the time, while others waited for busesto the town of Jibreen , on the southeastern outskirts of Aleppo, where many of those fleeing are being housed. 
 
 A Syrian commander told CNN that more than 2,000 people had passed through the Maysaloon crossing point since 10 Tuesday night. 
 
 "We have suffered a lot," said a man in his early 60s who was traveling with eight relatives and asked not to be named. 
 
 "We've been deprived of food -- the amount of bread we were being given wasn't enough to feed my family," he said. "My vision has been affected by the lack of food." 
 
 Syrians escaping war-torn eastern Aleppo describe days of hunger and fear of airstrikes. 
 
 His family received one loaf of bread between two people every three days, which wasn't enough to feed them, he said. 
 
 Shrapnel from an airstrike hit one of his sons, but the man said he was mainly concerned that family members would starve if they stayed in eastern Aleppo. 
 
 A girl named Ghazal, only 7 days old, was born at the height of the fighting in eastern Aleppo. 
 
 The CNN crew also saw Syrian soldiers carrying old and weak people out of Agheour. There were also families with small infants, the youngest a girl named Ghazal who was 7 days old. Two men helped carry an elderly woman on a chair. 
 
 Rebel forces controlled the Agheour area for at least 3½ years before it was retaken by Syrian government forces Tuesday night. 
 
 UNICEF said in a statement Wednesday that some 31,500 people had been displaced from eastern Aleppo in 10 days. Estimates indicate at least half are children, it said. 
 
 A joint statement Wednesday by the leaders of Canada, France, Germany, Italy, Britain and the United States called for an "immediate ceasefire" and condemned the Syrian regime and Russia for their actions in Aleppo. 
 
 It called on the United Nations to hold accountable those who have committed "war crimes" and said "only a political settlement can bring peace for people in Syria." 
 
 While it is difficult to estimate how many people are still in eastern Aleppo, according to the statement some 200,000 civilians -- including many children -- are cut off from food and medical supplies there. 
 
 Resident: Death better than fleeing to regime 
 
 Abdulkafi al-Hamdo, a teacher and father of a 9-month-old baby, is one of those trapped in the remaining rebel-held area under heavy bombardment. 
 
 JUST WATCHED 'I am going to be killed' in Eastern Aleppo Replay More Videos ... MUST WATCH 'I am going to be killed' in Eastern Aleppo 04:39 
 
 "I get up (to) the sound of planes, feeling cold, not finding suitable food for breakfast and no clean water to drink. I go out to see my people in pain and fear," he told CNN via text message. 
 
 Many people "are dying without finding someone to bury them," he said. 
 
 Asked if he and his family would leave, he replied, "Where? Regime area? Death is much better. How can we go back to someone who killed our brothers, sisters and children?" 
 
 Hamdo said his wife could no longer breast-feed and their baby is hungry and crying all the time. They feed her some crushed rice and bread dipped in tea, he said. 
 
 Intense, continuous shelling 
 
 Activists inside besieged eastern Aleppo told CNN that heavy artillery shelling and airstrikes were pounding the area Wednesday. The shelling is intense and doesn't show any signs of ceasing, they said. 
 
 JUST WATCHED Russia's efforts to win Syrian hearts and minds Replay More Videos ... MUST WATCH Russia's efforts to win Syrian hearts and minds 02:32 
 
 Activists with the Aleppo Media Center said the regime "was able to capture the neighborhood of Tareeq al-Bab after capturing al-Muwasalt neighborhood, as well as al-Shaar, Karm al-Jabal and several neighborhoods in the old city of Aleppo such as Bab al-Hadeed, Agheour, Bab al-Nasser, al-Bayada and Qadi Askar" after rebel forces withdrew. 
 
 Aleppo Media Center activists said regime forces had reached the Citadel in the old city of Aleppo but not the main gate. 
 
 Rebels call for humanitarian ceasefire 
 
 Rebels in eastern Aleppo have called for an immediate five-day humanitarian ceasefire and for the evacuation of about 500 emergency cases under UN supervision, according to a statement released in the name of the Aleppo City Leadership Council. 
 
 Shelling and aerial bombardment have heavily damaged Aleppo's old city. 
 
 The rebel group urges any civilians who wish to leave Aleppo be allowed to flee to the northern countryside, calling the northwestern province of Idlib "not a safe area" due to recent airstrikes on towns and villages. 
 
 "Once the humanitarian situation has been alleviated in Aleppo city, the parties concerned can negotiate the future of the city," the statement said. 
 
 The state-run Syrian Arab News Agency reported Wednesday that the Syrian army had "restored security and stability" to more than a dozen Aleppo neighborhoods in the past two days. It also said repairs had begun on the Aleppo airport road after the Syrian army captured the area. 
 
 Syrian President Bashar al-Assad, whose forces are backed by Russia, has said "terrorists" must be driven out to protect civilians. 
 
 UN resolution vetoed 
 
 Russia and China on Monday vetoed a UN Security Council resolution calling for a ceasefire in Aleppo to allow desperately needed aid into the war-ravaged zone. 
 
 The United Nations has repeatedly called for safe passage for its humanitarian staff, but it said the Syrian government and Russia have failed to guarantee it. 
 
 Russia's Defense Ministry reported Wednesday that a Russian military officer, Col. Ruslan Galitsky, had died from injuries sustained when rebel fighters shelled a residential area in western Aleppo, according to Russia's state-run Tass news agency.
– Heavy shelling was reported today in Aleppo and Damascus, as government forces and rebels both gear up for a major showdown, reports Reuters. The Syrian military is sending convoys of tanks, troop carriers, and other hardware to the vital central cities, leaving rebels in control of much of the countryside. Activists claimed that rebels controlled about half of Aleppo, and, outgunned by the military, they doubt rebels can hold the city, reported the New York Times. Other developments: Rebels are rushing to stockpile munitions in Aleppo, reports the BBC, and setting up checkpoints and snipers even as thousands of residents flee the city. One resident in a Palestinian refugee camp in southern Damascus reported heavy shelling in the south of the city, beginning around 7am and continuing for three hours. As government forces pull out of the Kurdish parts of Syria to prepare for the large offensive against the rebels in Aleppo and Damascus, Kurds are using the withdrawal to fly the Kurdish flag, asserting their independence, reports the Guardian.