Beirut: Up to 20,000 Syrians fleeing a government advance in northern Aleppo province have gathered at a border crossing with Turkey, the United Nations said on Friday.
"It is estimated that up to 20,000 people have gathered at the Bab al-Salama border crossing and another 5,000 to 10,000 people have been displaced to Azaz city" nearby, said Linda Tom, a spokeswoman for the UN`s Office for the Coordination of Humanitarian Affairs.
She said another 10,000 people were estimated to have been displaced to the Kurdish town of Afrin, elsewhere in northern Aleppo.
"There is currently one IDP (internally displaced persons) camp in Afrin district and plans are under way to expand the camp," she told AFP.
"The fighting has also disrupted major aid and supply routes from the Turkish border," she added.
"Humanitarian organisations are responding to the needs of those displaced, but ongoing military conflict is making access to populations in need increasingly difficult."
Syrian government forces backed by allied militias and Russian airpower began a major offensive in northern Aleppo on Monday, seizing a string of villages from rebels and severing their main supply route to Turkey.
The advances have prompted tens of thousands of people to flee and left the opposition and civilians in rebel-held eastern Aleppo city virtually encircled.
On Thursday, Turkish Prime Minister Ahmet Davutoglu warned that up to 70,000 people were heading to his country, with 10,000 already waiting at the border.
Turkey already hosts about 2.5 million Syrian refugees.