As many as 15,000 FSA rebels have been moved east of Afrin, reported Jazeera.

A convoy of at least 20 buses was transported under heavy security to Turkey's southern province of Hatay from the province of Kilis, Al-Jazeera said citing local Turkish media.

Turkey says it is intervening in Syria’s north to defeat Kurdish fighters affiliated with the Kurdistan Workers’ Party, a rebel group recognized as terrorists by the United States and European Union. The plan puts Ankara in direct political conflict with Washington, a NATO ally, which is using the fighters to battle Islamic State (IS).

"The situation in Afrin is heating up. There's been an increasing shelling from Turkey into Afrin," Dekker said.

"This is in line with the political rhetoric coming out of Ankara over the last week or so."

Reporter’s code: 50101