The number of Syrian refugees massed on the border with Turkey after fleeing a government offensive near the northern city of Aleppo has nearly doubled in the past 48 hours.
Suleyman Tapsiz, the governor of the Turkish border province of Kilis, said 35,000 refugees had reached the border area -- up from an estimated 20,000 on February 5.
Tapsiz told reporters that another 70,000 Syrians could be expected if Russian air strikes and military advances by the Syrian regime continued.
He said Turkey would provide aid to the displaced within Syria but would only open the gates in the event of an "extraordinary crisis."
Fierce fighting has been reported between the rebels and government forces, backed by Russian air strikes, who have virtually surrounded Aleppo, a rebel stronghold.
The Britain-based monitor the Syrian Observatory for Human Rights said clashes on February 5 around Ratyan, a town near Aleppo, cost 120 lives on both sides.
The UN's Office for the Coordination of Humanitarian Affairs said it estimated "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.
Around 300,000 people are believed to be trapped in Aleppo after the rebels' main supply route was cut off by government forces in an offensive that scuppered UN-mediated peace talks in Geneva this week.
