ANKARA, Turkey (AP) -- Turkish troops fired at Syria again Friday, responding to another mortar shell from Syria that struck Turkish territory, the country's state-run news agency said.
The shelling came hours after Prime Minister Recep Tayyip Erdogan called on Syria not to test Turkey's patience.
The Anadolu Agency quoted Gov. Celalettin Lekesiz as saying a mortar shell hit 50 meters (yards) inside the border in a rural area near the village of Asagipulluyaz in Hatay province.
No one was hurt by the mortar, but Turkish troops based in the area immediately responded with fire, he said.
Turkish artillery has fired at Syrian targets for two straight days after shelling from Syria killed five Turkish civilians on Wednesday.
Turkey's parliament voted Thursday to allow cross-border military operations in Syria, sharply escalating tensions between the two former allies.
Erdogan on Friday renewed a call for Syria not to challenge Turkey.
"I call on those who try to test Turkey's limits and determination: That would be a grave mistake. We are not bluffing," he said.
The Syrian uprising against President Bashar Assad erupted in March 2011 and has gradually morphed into a bloody civil war, killing more than 30,000 people, according to activists.