The Turkish military returned fire after a mortar bomb shot from Syria landed in countryside in southern Turkey on Saturday, the state-run Anatolian news agency reported.
It was the latest in a series of Turkish retaliatory attacks in response to mortar bombs and shelling by Syrian forces that have killed five Turkish civilians further east along the border.
The strikes and counter-strikes have been the most serious cross-border violence seen so far in Syria's conflict, and underlined how it could destabilise the region.
Turkish Prime Minister Tayyip Erdogan said on Friday his country did not want war but warned Syria not to make a fatal mistake by testing its resolve. Damascus has said the mortars landed in Turkey accidentally.
Anatolian said the mortar round hit countryside near Guvecci village in the Yayladagi area amid intense clashes on the Syrian side of the border in Idlib province.
"Military units on the Turkish border launched retaliatory fire immediately," the agency said, without identifying its source or mentioning any casualties.