The deaths occurred when a shell hit a house in the town of Suruc, adjacent to Kobane in Syria which is under the control of the Kurdish People's Protection Units (YPG) militia, the agency said.

Kobane was the site of a major months-long battle in 2017 and 2018 by Kurdish forces to retake the town from the Islamic State group.

Turkey launched a military offensive on Wednesday against the YPG, which it considers a "terrorist" off-shoot of Kurdish insurgents in Turkey.

Defence Minister Hulusi Akar said 342 YPG "terrorists" had so far been killed in the operation, according to Anadolu.

"The operation is going as planned," he said. "We are being extremely careful to ensure no civilians are harmed."

Turkish media earlier reported that two journalists were injured by Kurdish militant fire in another border town of Nusaybin in Mardin province.

Kurdish forces barraged Turkish border towns throughout Thursday, killing five civilians.