Turkish artillery struck back on Monday after a shell fired from neighbouring Syria ploughed into Turkish territory without causing any casualties, the state-run news agency reported.
The shell struck near the village of Besaslan in southern Hatay province amid escalating clashes between Syrian loyalist troops and rebels in the Syrian town of Haram, just across the border, Anatolia said.
Later in the day, one more shell fired from Syria landed 500 metres (yards) from Besaslan, according to Anatolia. It did not say whether Turkish border units responded to the latest shell.
Turkey has systematically retaliated to every cross-border shelling since Syrian fire killed five Turks on October 3.
One-time allies Turkey and Syria fell out after Ankara joined Arab and Western countries in urging Syrian President Bashar al-Assad to halt his violent crackdown on the popular uprising that erupted in March last year and has now turned into a civil war.
Turkey supported a proposal by international peace envoy Lakhdar Brahimi for the regime and the rebels top lay down their arms during the Eid Al-Adha Muslim holiday but the truce never took hold.