Turkey's Prime Minister Recep Tayyip Erdogan said on Sunday that a Syrian plane had violated the country's airspace.

"Our F-16s took off and hit this plane. Why? Because if you violate my airspace, our slap after this will be hard," he told supporters in northwest Turkey during a rally ahead of local elections on March 30.

Syrian rebels have been battling government forces loyal to Syria's president, Bashar al-Assad, for the border post of Kasab.

Authorities in Syria accused Turkey of "flagrant aggression" for attacking the fighter jet, with a military source telling the official SANA news agency that the jet was inside Syrian territory as it attacked rebels near the Syria-Turkey border.

According to the Britain-based monitoring group the Syrian Observatory for Human Rights, the plane came down on the Syrian side of the border. State television quoted a military source as saying the pilot managed to eject.

It's not the first time Turkey has shot down a Syrian military aircraft - a helicopter was shot down in September 2013.

se/kms (dpa, AFP, Reuters, AP)