KILIS, Turkey — More than 1,300 Syrians fled to Turkey overnight to escape the civil war, as rebels tried to expand their hold inside Syria's largest city despite two weeks of withering counterattacks by President Bashar Assad's troops.
Mr. Assad, meanwhile, met in Damascus with an envoy from key ally Iran and was quoted by Syrian official media as vowing to fight on.
Heavily armed government troops have been shelling rebel-controlled parts of Aleppo, particularly Salaheddine and other districts on the southwestern edge of the strategic city.
Aleppo-based activists said clashes were going on Tuesday near the historic city center. That suggests the rebels were making some inroads in Aleppo, which lies some 25 miles from the Turkish border.
Intense government bombardment of the Syrian town of Tal Rafaat closer to the border sent scores of people spilling into Turkey for safety, according to the activists.
A Turkish government official said 1,328 Syrian refugees had crossed the border by midmorning -- nearly double the number of refugees that reached Turkey on Monday. The official spoke on the condition of anonymity in line with government rules.
Close to 48,000 Syrians have now found refuge in Turkey, which has served as a staging ground for rebels fighting Mr. Assad's regime.
"We are expecting a massacre in Aleppo. The regime is bringing reinforcements to the city because they believe that if Aleppo falls, the regime will fall," said a Syrian refugee in Turkey who identified himself as Abu Ahmad.
"The city is being bombed from the air and ground," he said, adding he was in daily contact with residents still in the city.
In Baghdad, at least 22,300 Iraqis who had fled to Syria several years ago have streamed home in the past three weeks, U.N. officials in Baghdad said Tuesday, preparing for more refugees fleeing the escalating Syrian civil war.
The returning Iraqis have been joined by some 3,600 Syrians who have crossed into Iraq since July 23, when Baghdad announced it was opening its western borders to refugees. The Syrians are being kept near the border, evoking some complaints.
The influx represents a stark turnaround from the bloody years following the 2003 U.S.-led invasion of Iraq, when waves of refugees fled in the opposite direction.
Despite a ferocious crackdown, rebels in Syria have grown more confident and are using increasingly bolder tactics both in Aleppo and in the Syrian capital, Damascus.
In a brazen, daylight attack, rebels on Saturday abducted a group of 48 Iranians near Damascus, branding them as spies assisting in Mr. Assad's crackdown.
Iran said those captured when their bus was commandeered were pilgrims visiting a Shiite shrine on the outskirts of Damascus. On Tuesday, Iran's Foreign Ministry said it holds the U.S. responsible for the fate of the abducted Iranians.