The Bush administration has put Syria on notice it has a ``special responsibility'' to curb violence in areas of Lebanon under Syrian control, the State Department said Wednesday. With the U.S. Embassy in Beirut closed, the United States is assessing blame for the mounting death toll since Gen. Michel Aoun, the last major Christian holdout, gave up his struggle against Syrian forces 11 days ago. The most recent prominent victim was Dany Chamoun, a Christian leader who also opposed Syrian influence. He, his wife and two small children were slain in their Beirut apartment last weekend. No one has claimed responsibility. ``We have seen the many press reports of atrocities carried out in East Beirut since the surrender of Gen. Aoun,'' Margaret D. Tutwiler, the State Department spokeswoman, said. ``We do not have firsthand knowledge which could confirm those reports. However, the reports themselves are enough to shock and horrify,'' The U.S. official added: ``if these reports are true, whoever is responsible the United States would condemn them in the strongest terms.'' The Bush administration had urged Aoun to end his resistance. Aoun has taken refuge in the French embassy. ``We have told the Syrians they have a special responsibility, given their control over parts of Lebanon, to ensure that such abuses do not take place in areas under their control,'' Ms. Tutwiler said, reading from a prepared statement. ``There is no ambiguity in the message we have sent to Syria on this point.'' Syria, which has influence over the Lebanese government headed by President Elias Hrawi, is a key Arab ally of the United States in its campaign against Iraq's occupation of Kuwait. Some 4,000 Syrian troops are in Saudi Arabia to help defend the kingdom against Iraqi attack. Ms. Tutwiler said Assistant Secretary of State John H. Kelly had met with Syrian Ambassador Walid al-Moualem here while Edward Djerejian, the U.S. ambassador to Syria, had met with Foreign Minister Farouk al-Shara in Damascus. Also, the spokeswoman said, Kelly met Tuesday and several times before then with the Lebanese ambassador, Nassib Lahoud.