Seif al-Islam, his father and Libya's intelligence chief were indicted earlier this year for allegedly ordering, planning and participating in illegal attacks on civilians in the early days of the violent crackdown on anti-regime protesters. 
 
 In the Netherlands, the prosecutor at the International Criminal Court, Luis Moreno-Ocampo, said his office would talk to the rebels on Monday about Seif al-Islam's transfer for trial. "It is time for justice, not revenge," Moreno-Ocampo told the AP. 
 
 'Time for justice, not revenge' Citing a source close to Gadhafi's inner circle, NBC News reported that Seif al-Islam had tried to flee Tripoli while disguised as a women. 
 
 "Whether or not Gadhafi reads the tea leaves the same way is the big question," the official said. 
 
 Referring to news that Gadhafi's sons Seif al-Islam, his onetime heir apparent, and Mohammed had been arrested and were in rebel custody, the U.S. official said, "We could be watching the game changer unfolding." 
 
 As international news agencies broadcast video of huge crowds celebrating in Benghazi, the rebels' eastern headquarters, a U.S. official told NBC News that "the battle for Tripoli is clearly under way, and what has often seemed impossible — the fall of Gadhafi — may now be attainable." 
 
 NBC News was not able to independently confirm the reports. Other top officials were reported to be fleeing, led by Prime Minister Al Baghdadi AlMahmoudi, who was spotted Monday morning in Jaraba, Tunisia, Al-Jazeera reported. 
 
 Another major Arabic news agency, Al Arabiya, reported that indications were that Gadhafi may be in Tajoraa Hospital. 
 
 Al-Jazeera's Arabic-language service reported that officers who had defected to the rebels found Gadhafi overnight near Tajoraa Hospital east of Tripoli. Gadhafi resisted, and two of the officers who tried to arrest him were killed, said the news agency, quoting a military source. 
 
 "The traitors are paving the way for the occupation forces to be deployed in Tripoli," he said, calling on his supporters to march in the streets of the capital and "purify it" from "the rats." 
 
 'Traitors' Gadhafi delivered a series of defiant audio messages on state television Sunday night. He acknowledged that the opposition forces were moving into Tripoli and warned that the city would be turned into another Baghdad. 
 
 "The future of Libya is now in the hands of the Libyan people," the president said. 
 
 President Barack Obama said in a statement late Sunday from vacation in Martha's Vineyard, Mass., that "Tripoli is slipping from the grasp of a tyrant" and that Gadhafi's regime "is showing signs of collapsing." 
 
 Rebel fighters from the west swept over 20 miles in a matter of hours Sunday, taking town after town and overwhelming a major military base as residents poured out to cheer them. At the same time, Tripoli residents secretly armed by rebels rose up. 
 
 The startling rebel breakthrough, after a long deadlock in Libya's 6-month-old civil war, was the culmination of a closely coordinated plan by rebels, NATO and anti-Gadhafi residents inside Tripoli, rebel leaders said. 
 
 Hundreds of people remained in the streets of the capital Monday morning. Many of them were armed, and they fired repeatedly at propaganda posters of Gadhafi. 
 
 Men celebrate the arrival of rebel fighters in Tripoli in the streets of Misrata, Libya, on Monday. 
 
 Earlier, rebels waving opposition flags and firing into the air drove into Green Square, a symbolic showcase of the government until it was recently used for mass demonstrations in support of Gadhafi. Rebels immediately began calling it Martyrs' Square. 
 
 Two of Gadhafi's sons were captured by the rebels but the whereabouts of Gadhafi himself, one of the world's longest ruling leaders, were unknown. 
 
 A rebel spokesman also told Al-Jazeera that some pro-Gadhafi forces were still fighting and controlled 15 to 20 percent of Tripoli. 
 
 Bab al-Aziziya, a sprawling compound that long served as the command center for the regime, has been heavily damaged by repeated NATO airstrikes over the past five months. 
 
 Tripoli resident Moammar al-Warfali, whose family home is next to Bab al-Aziziya, said tanks rolled out from the compound after a group of rebels tried to get in. He said there appeared to be only a few tanks belonging to the remaining Gadhafi forces that have not fled or surrendered. 
 
 Nouri Echtiwi, another rebel spokesman in Tripoli, told Reuters: "Four hours of calm followed the street celebrations. Then tanks and pick-up trucks with heavy machine guns mounted on the back came out of Bab al-Aziziya ... and started firing and shelling. They fired randomly in all directions whenever they heard gunfire." 
 
 Rebel spokesman Mohammed Abdel-Rahman said tanks emerged from the complex, known as Bab al-Aziziya, and began firing shortly after dawn. 
 
 Heavy fighting was reported near Moammar Gadhafi's compound Monday as government forces launched a fightback after rebels swept into the heart of the Libyan capital and crowds took to the streets to celebrate what they saw as the end of the dictator's four decades in power. 
 
 P.J. Crowley, former chief spokesman for the State Department, said in an interview with msnbc TV that the swift takeover of the capital was "simply remarkable." 
 
 Crowley cautioned that the world community would need to act just as swiftly to ensure stability. The National Transitional Council, a committee formed in March by anti-Gadhafi forces, has been "preparing for this day," but it would have been surprised by the overnight takeover, he said. 
 
 "They will have to move swiftly," Crowley said, asking: "What will happen to their security services? ... What kind of justice system will we have?" 
 
 Obama keeps full vacation day after Libya briefing 
 
 Earlier Sunday, the rebels overran a major military base defending the capital, carted away truckloads of weapons and raced to Tripoli with virtually no resistance. 
 
 The rebels' surprising and speedy leap forward was packed into just a few dramatic hours. By nightfall, they had advanced more than 20 miles to Gadhafi's stronghold. 
 
 Thousands of jubilant civilians rushed out of their homes to cheer the long convoys of pickup trucks packed with rebel fighters shooting into the air. Some were hoarse, shouting, "We are coming for you, frizz-head," a mocking nickname for Gadhafi. In villages along the way that fell to the rebels one after another, mosque loudspeakers blared, "Allahu Akbar," or "God is great." 
 
 "We are going to sacrifice our lives for freedom," Nabil al-Ghowail, 30, a dentist, said as he held a rifle in the streets of Janzour, a suburb just 6 miles west of Tripoli. Heavy gunfire erupted nearby. 
 
 As town after town fell and Gadhafi forces melted away, the mood turned euphoric. Some shouted: "We are getting to Tripoli tonight." Others were shooting into the air, honking horns and yelling "Allahu Akbar." 
 
 Once the rebels reached Tripoli, a convoy of more than 10 trucks entered the neighborhood of Ghot Shaal on the western edge of the city and set up checkpoints. 
 
 The rebels moved on to the neighborhood of Girgash, about a mile and a half from Martyrs Square. They said they came under fire from a sniper on a rooftop in the neighborhood. 
 
 Sunday's first breakthrough came when hundreds of rebels fought their way into a major symbol of the Gadhafi regime — the base of the elite 32nd Brigade, commanded by Gadhafi's son Khamis. Fighters said they met little resistance. 
 
 Hundreds of rebels cheered wildly and danced as they took over the compound filled with eucalyptus trees, raising their tricolor from the front gate and tearing down a large billboard of Gadhafi. 
 
 Inside, they cracked open wooden crates labeled "Libyan Armed Forces" and loaded their trucks with huge quantities of munitions. One of the rebels carried off a tube of grenades, while another carted off two mortars. 
 
 Across the street, rebels raided a huge warehouse, making off with hundreds of crates of rockets, artillery shells and large-caliber ammunition. The warehouse had once been used to store packaged foods, and in the back, cans of beans were still stacked toward the ceiling. 
 
 The prisoners had been held in the walled compound, and when the rebels rushed in, they freed more than 300 of them. 
 
 "We were sitting in our cells when, all of a sudden, we heard lots of gunfire and people yelling 'Allahu Akbar.' We didn't know what was happening, and then we saw rebels running in and saying, 'We're on your side.' And they let us out," said Majid al-Hodeiri, 23, of Zawiya. He said he was captured four months ago by Gadhafi's forces and taken to the base, where he said he was beaten and tortured. 
 
 Many of the prisoners looked disoriented as they stopped at a gathering place for fighters several miles away from the base. Some had signs of severe beatings. Others were dressed in tattered T-shirts or were barefoot. 
 
 Crackdown fuels rebellion 
 
 The uprising against Gadhafi broke out in mid-February, and anti-regime protests quickly spread across the vast desert nation of 6 million people. A brutal regime crackdown quickly transformed the protests into an armed rebellion. Rebels seized Libya's east, setting up an internationally recognized transitional government there, and two pockets in the west, the port city of Misrata and the Nafusa mountain range. 
 
 Gadhafi clung to the remaining territory, and his forces failed to subdue the rebellion in Misrata, Libya's third-largest city, and in the Nafusa mountains. Since the start of August, thousands of rebel fighters, including many who had fled Gadhafi-held cities, joined an offensive that was launched from the mountains toward the coast. 
 
 The fighters who had set out from the mountains three weeks ago rushed toward Tripoli on Sunday, starting out at dawn from a village just east of the coastal city of Zawiya. Only a day earlier, the rebels had claimed full control of Zawiya, an anti-regime stronghold of 200,000 people and home to Libya's last functioning oil refinery. 
 
 Rebels said Saturday that they had launched their first attack on Tripoli in coordination with NATO, and gunbattles and mortar rounds rocked the city. NATO aircraft also made heavier-than-usual bombing runs after nightfall, with loud explosions booming across the city. 
 
 NATO has conducted airstrikes in Libya since the end of March to fulfill a U.N. mandate calling for military action to protect civilians. Oana Lungescu, a NATO spokeswoman, said the Western alliance would continue to enforce its mandate. ||||| Read a day-by-day account of the battle for control of key areas of Libya and for the latest on what's next for Libya, the opposition and Moammar Gadhafi, tune in to "AC360º" at 10 p.m. ET Thursday on CNN. 
 
 Ras Lanuf, Libya (CNN) -- Libya's ragtag rebels in Zawiya succumbed Thursday to better armed and organized government soldiers after enduring a week of attacks that left the coastal city strewn with the debris of war. 
 
 The city's main Martyrs' Square was littered with the bombed-out, scorched carcasses of army tanks and other military vehicles. 
 
 Workers were sweeping up the evidence as supporters of Libyan leader Moammar Gadhafi chanted slogans and waved green flags. 
 
 "Today Zawiya, tomorrow Benghazi," ITV News' Bill Neely said a Gadhafi supporteer told him in a reference to Libya's main rebel-held city in the east. 
 
 Neely said he was the first reporter to reach the city center Thursday after the government wrested its control from the rebels. He said doctors had told him that scores of civilians had been wounded or killed in the siege; they called the onslaught a massacre, a war crime. He counted more than 20 freshly dug graves. 
 
 The city itself was quiet; shops were closed and houses appeared empty. The mosque's minaret was demolished, and spent bullets and other munitions lay on the ground with bloodied mlitary clothing. 
 
 State-run television broadcast video of weapons and ammunition reportedly left behind by the rebels, whom the reporter referred to as "terrorists, dogs and traitors," Neely said. 
 
 Government retaliation against the residents appears to have begun, said one man, who told ITV that government forces were carrying out house-to-house searches in Zawiya. "They start to arrest people, normal people," he said. "Some of them I know personally; they have nothing to do with what's happening." 
 
 Battles also raged in and around the eastern city of Ras Lanuf and many other cities, with the regime using planes and heavy artillery in its effort to reclaim areas that had been taken by the opposition. 
 
 Libya's state TV reported that "Ras Lanuf has been cleansed from the armed gangs connected to al Qaeda." A doctor who worked in Ras Lanuf said at least three people were killed and 30 wounded in fighting before the main hospital had to be evacuated. Doctors at a hospital in the city of al-Brega reported two deaths and more than 20 people wounded in fighting in Ras Lanuf. 
 
 Opposition forces could be seen retreating from the city. Some fighters said they had pulled back to a checkpoint five miles east of the city, but it was not clear who was in control of the city. 
 
 CNN's Ben Wedeman said the rebel forces appeared in disarray. "It's been a very chaotic effort on the part of the opposition fighters from the beginning," he said, adding that they had no command-and-control structure and little discipline. 
 
 He credited them for their enthusiasm and spirit, but added, "Once the going gets tough, the ranks start to fall apart and it descends into anarchy, chaos." 
 
 Saif Gadhafi, a son of Moammar Gadhafi and a prominent spokesman for the regime, vowed to retake eastern Libya as well and insisted his father still commanded support. "I receive hundreds of calls from the east daily and they are saying, 'Save us.' They are begging us and pleading for us to save them and my answer is two words. Listen to me and I want those armed groups to listen to me real well, and I want our people in the east to hear this as well: We're coming." 
 
 He bristled at the possibility of military intervention. "The Libyan people they will never welcome NATO or Americans," he said. "Libya is not a piece of cake; we are not a Mickey Mouse." 
 
 Though the Libyan government forces appeared to advance on the ground, the opposition gained momentum internationally. 
 
 The French government recognized the newly created Libyan opposition movement as the sole representative of the country and the British foreign secretary spoke to an opposition representative over the phone. 
 
 In response, Libyan state TV said the Gadhafi government would consider ending its relationship with France. 
 
 In the United States, Secretary of State Hillary Clinton announced plans to meet with opposition leaders. She said the United States was suspending relations with the Libyan Embassy in Washington, and an administration official added the embassy "must shut down." 
 
 But an official told CNN that "ending the operations of the Libyan Embassy does not mean we're cutting off diplomatic ties with Libya." 
 
 Protests against the 68-year-old Gadhafi began February 15 as anti-government demonstrators sought his ouster after nearly 42 years of rule, and the discontent devolved into a fierce and bloody civil war. 
 
 America's top U.S. intelligence official, James Clapper, took note of Libya's military prowess at a Senate Armed Services Committee meeting Thursday. He said Gadhafi is in the fight for the long haul, with military far superior to that of the opposition. 
 
 Clapper described the Libyan air defense as "substantial," saying it is the region's second-largest, after Egypt, but he did not address how fighting would fare against Libya if a no-fly zone or other military strategies were imposed. 
 
 He said Gadhafi has a lot of aircraft, although many are not operational. To "some extent," he said, the aircraft have been used for attacks, but they have caused more structural damage than injury. 
 
 In Brussels, Belgium, NATO defense ministers discussed the option of a no-fly zone over the North African country. Its secretary-general said any move to impose one would require a clear mandate from the United Nations. 
 
 NATO also decided to bolster its presence in the Mediterranean Sea and perform detailed planning on humanitarian assistance. 
 
 International military officials say the imposition of a no-fly zone could be complicated, but some opposition figures -- such as Mustafa Abdul-Jalil, a former justice minister who quit last month in protest and now heads the interim government in eastern Libya -- are advocating for the move. 
 
 Gadhafi has said that imposing such a zone would simply unite Libyans behind him. 
 
 Saying NATO is "united," "vigilant," and "ready to act," Anders Fogh Rasmussen, the group's secretary-general, said the body has begun round-the-clock airborne surveillance of Libya's airspace. 
 
 "Time is of the essence," he said, adding that the crisis requires "close international coordination" among organizations such as NATO, the United Nations, the European Union, the African Union, and the Arab League. 
 
 U.S. authorities have frozen $32 billion in assets tied to the Libyan regime, White House spokesman Jay Carney said. 
 
 British Foreign Secretary William Hague spoke by telephone with Mahmoud Jabril, the National Transitional Council's special envoy. 
 
 He said European foreign ministers on Thursday talked about how the EU should react "to the continuing appalling and unacceptable actions" of the regime. 
 
 Hague "made clear that planning was under way on a full range of responses, including the possible establishment of a no-fly zone," the Foreign Office said in a statement. "It would need international support, a clear trigger and a legal basis. He also said that another diplomatic mission would be sent to Benghazi shortly." 
 
 At the NATO meeting, U.S. Secretary of Defense Robert Gates said a no-fly zone option was still being considered, but was only in the planning stages. Gates added that any military response to Libya would need the United Nations to sanction it. 
 
 Russian President Dmitry Medvedev signed an executive order banning the sale to Libya of arms, ammunition and military equipment, according to the Kremlin's website. 
 
 The Council of the European Union Thursday announced it will extend restrictions against Libyan entities. 
 
 As for Gadhafi's government, it has sought to influence international sentiment, announcing that its secretary of state for international relations will travel to Portugal, Greece and Malta on an exploratory, fact-finding mission that may include other destinations. 
 
 The country has also invited British, French, Dutch and German fact-finding teams to examine reports of aerial bombardment and massacres. None has taken up Gadhafi on the offer. 
 
 Death toll estimates have ranged from more than 1,000 to as many as 2,000. 
 
 As of Thursday morning, the war had forced out nearly 250,000 people, many of them poor migrant workers who have been stranded at both the Tunisian and Egyptian borders, the U.N. refugee agency said. 
 
 The United States will soon send disaster relief teams into eastern Libya, White House National Security Adviser Thomas Donilon said. He said the teams' activities should not be viewed as military operations. 
 
 U.N. High Commissioner for Human Rights Navi Pillay on Thursday condemned the detention and possible torture by Libyan authorities of a BBC news team working to cover the conflict in Zawiya. The journalists, released from detention in Libya Wednesday, told of beatings and mock executions. 
 
 The Guardian, a British daily newspaper, reported that one of its correspondents, Ghaith Abdul-Ahad, was missing. 
 
 He was traveling with Andrei Netto of the Brazilian newspaper Estado, who was detained by authorities while reporting from Libya, the Guardian said. Netto was released Thursday and was to leave the country Friday. 
 
 CNN's Ben Wedeman, Pam Benson, Jill Dougherty, Whitney Hurst, Jonathan Wald and Journalist Saskya Vandoorne contributed to this report
– It was a bad day for rebel forces in Libya, but in the streets of Tripoli people were celebrating—in part because they believed the news state-run television was broadcasting. David Green of NPR talked to people in a crowd of a few hundred Moammar Gadhafi supporters, who said they believed that al-Qaeda was responsible for the uprising, a message the state-run media has been heavily propagating. The regime also used state television to attempt to undermine rebel morale today, as ministers announced that they’d give amnesty to anyone who gave up their weapons, the New York Times reports. At the same time, loyalist forces gained ground militarily, pushing rebels out of the coastal oil town of Brega, according to the Wall Street Journal. There were also a series of mysterious explosions in Benghazi, along with some robberies and the murder of an al-Jazeera journalist, prompting rebel authorities to round up Gadhafi supporters.