BEIRUT — UN observers investigated the latest reported massacre in Syria, entering a village Saturday where activists say regime forces killed dozens of people the past week, as Turkey's prime minister blasted Damascus' leadership, warning that the Syrian people will “make them pay” for such mass killings. An 11-vehicle team of observers went into the central village of Treimsa after receiving confirmation a ceasefire was in place, a spokesman for the UN mission in Syria, Ahmad Fawzi, said. It is the first outside look into the village where activists say at least 230 people were killed by government troops who shelled the town before moving in alongside pro-regime militiamen. “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 Thursday when its forces clashed with “armed gangs” that were terrorizing village residents. The regime refers to its opponents as terrorists and gangsters. On Friday, the United Nations blamed government forces for the Treimsa assault, saying UN observers deployed near the village saw government troops using heavy weaponry and attack helicopters against it. World leaders have heaped criticism on President Bashar Al-Assad's regime over the incident, which was the latest in a series of reported mass killings by regime forces in recent months. Anti-regime activists say more than 17,000 people have been killed since the uprising against the regime began in March 2011. The killings cast new doubt over the international community's efforts to find a diplomatic solution to the crisis. 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 over the Treimsa 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.” A suicide bomber blew up his car in the closest main town to Treimsa Saturday, killing four. — AP