UN team investigates massacre in Syria village Updated at 630 p.m. ET: United Nations observers found blood, burned homes and signs of artillery fire in the Syrian village of Tremseh on Saturday but were unable to confirm activists' reports that about 220 people were massacred in an attack that prompted international outrage. The investigation came along with two other key developments in the reported mass slaying by regime forces, who activists say have killed more than 17,000 people since the uprising against killings by President Bashar Assad's rule began in March 2011: Turkey's prime minister blasted Damascus' leadership, warning that the Syrian people will "make them pay" for such mass killings. The International Committee of the Red Cross now views fighting in Syria as an internal armed conflict - a civil war in layman's terms - crossing a threshold experts say can help lay the ground for future prosecutions for war crimes. On Saturday, an 11-vehicle team of observers went into the central village of Tremseh after receiving confirmation a cease-fire was in place, said spokesman for the U.N. mission in Syria Ahmad Fawzi. It was the first outside look into the village where activists say at least 150 people were killed by government troops who shelled the town before moving in alongside pro-regime militiamen. Anonymous / AP This image made from amateur video from Hama Revolution 2011 and accessed by AP video, purports to show a funeral for victims killed by violence that, according to anti-regime activists, was carried out by government forces in Tremseh, Syria, on Thursday. "We have sent a large integrated patrol today to seek verification of the facts," Fawzi said. Details of the killings remain unclear. The Syrian government says 50 people were killed in Tremseh Thursday when its forces clashed with "armed gangs" terrorizing village residents. The regime refers to its opponents as terrorists and gangsters. On Friday, the United Nations blamed government forces for the Tremseh assault, saying U.N. observers deployed near the village saw government troops using heavy weaponry and attack helicopters against it. US source: Syria is moving its chemical weapons "The attack on Tremseh appeared targeted at specific groups and houses, mainly of army defectors and activists," the spokesman for the U.N. observer mission to Syria said later in an emailed statement. A wide range of weapons were used, including artillery, mortars and small arms. Opposition activists say government forces killed about 220 people in the village. U.N. observers said they had found a burned school and fire-damaged houses. World leaders have heaped criticism on Assad's regime over the Tremseh incident. A suicide bomber blew up his car in the closest main town to Tremseh on Saturday, killing three civilians and one security officer, Syria's state news agency said. SANA said the attacker, who camouflaged the bomb with onions, detonated the explosives in the town of Muhrada. Warning from Turkey The prime minister of Turkey - once an ally of Assad before turning against him early on in the uprising over the regime's bloody crackdown, blasted Syria's leadership on Saturday over the Tremseh killings. "These vicious massacres, these attempts at genocide, these inhuman savageries are nothing but the footsteps of a regime that is on its way out," Recep Tayyip Erdogan said. Sooner or later, these tyrants with blood on their hands will go and the people of Syria will in the end make them pay. Donatella Rovera of Amnesty International discusses reports of bloodshed on a major scale in the central part of Syria. Red Cross declaration The Red Cross, guardian of the Geneva Conventions setting down the rules of war, previously classed the violence in Syria as localized civil wars between government forces and armed opposition groups in three flashpoints - Homs, Hama and Idlib. But hostilities have spread to other areas, leading the Swiss-based agency to conclude the fighting meets its threshold for an internal armed conflict and to inform the warring parties of its analysis and their obligations under law. There is a non-international armed conflict in Syria. Not every place is affected, but it is not only limited to those three areas, it has spread to several other areas," ICRC spokesman Hicham Hassan told Reuters in response to a query. "That does not mean that all areas throughout the country are affected by hostilities," he said. The qualification means that people who order or commit attacks on civilians including murder, torture and rape, or use disproportionate force against civilian areas, can be charged with war crimes in violation of international humanitarian law.