"Four artillery rounds were fired on October 15 against a position near the town of Azaz held by the Islamic State of Iraq and the Levant (ISIL)," an Al-Qaeda affiliated group, the army chief of staff said in a statement yesterday.
The shelling came in response to a mortar round that was fired from Syrian territory and fell without detonating near a police post inside Turkey, it said.
Turkey has for more than a year responded when shells from Syria have landed on its territory, but this marked the first time that it has specifically targeted Islamist extremists.
Across the north and east, the Islamic State of Iraq and the Levant (ISIL) has set up checkpoints on roads to border crossings, and opened fronts to crush other rebel groups fighting to oust embattled Syrian President Bashar al-Assad.
Turkey has cut off ties with the regime in Damascus since Assad's deadly crackdown on popular dissent and has so far taken in more than 500,000 Syrian refugees.