Thousands flee Palestinian camp near Damascus, fearing attack BEIRUT - Thousands of residents were fleeing a densely populated Palestinian district outside Damascus Monday amid rumors that Syrian government forces were massing and poised to attack. Syrian authorities say cadres of "terrorists" - the government's designation for the country's rebels - have infiltrated the Yarmouk camp, a sprawling urban enclave on the southern fringes of the capital. Yarmouk is home to about 300,000 people, half of them of Palestinian origin. Opposition activists said Syrian warplanes attacked the camp Sunday, killing at least eight people, including several outside a mosque. The incident marked the first time Yarmouk was targeted in an aerial bombardment, the opposition said. Gunfire and shelling Sunday killed at least a dozen other people, activists said, in what appeared to be the bloodiest day in Yarmouk since the start of the 21-month-old rebellion against President Bashar Assad. On Monday, rumors of an impending government assault sent many Yarmouk residents scrambling for safety in other Damascus-area neighborhoods, the United Nations said. At least 2,000 others fled to nearby Lebanon. "There were rumors that the regime forces are giving people a deadline of 6 o'clock in the evening to leave the place," said one Yarmouk resident, a student, 22, who arrived in Lebanon on Monday but didn't want his name used for security reasons. Sunday's clashes lasted well into Monday, he said, adding that extensive damage had left many people homeless and living on the streets. The U.N. issued a statement Monday saying it was "gravely concerned" about the safety of Palestinian refugees in Syria. It appealed to all sides in the conflict "to refrain from actions that endanger civilian lives and property." Before Sunday's violence, many Syrians fleeing attacks elsewhere in the country had moved to Yarmouk, considering it relatively safe. Still, there had been several mortar strikes in the camp in recent months and reports of periodic fighting between pro- and anti-Assad factions. Several neighborhoods adjacent to or near Yarmouk have seen heavy fighting between rebels and government troops. Syria is home to about 500,000 Palestinians, mostly descendants of the original refugees who came when Israel was established in 1948. Palestinian leaders have urged their people to stay out of Syria's conflict, but those who live there appear to be split. Some support the government and have even manned pro-Assad "popular council" militias in Yarmouk. Others sympathize with the rebels, and some have joined the armed rebellion. On Tuesday, Syrian Foreign Minister Walid Moallem warned Palestinians "to refrain from supporting or harboring these armed group[s] which are intruders to the camp." He urged Palestinians help to "expel" the rebels. Special correspondent Nabih Bulos in Amman, Jordan, contributed to this report.