"Four of them were killed when an air strike hit their car while fleeing" in Tal Abyad, Rami Abdel Rahman, the head of the Syrian Observatory for Human Rights, said.

The other three were killed by snipers around the border town, which has been one of the main targets of the assault Turkey and its proxies launched on Kurdish-controlled areas in Syria on Wednesday.

According to the UK-based monitor, a total of 17 civilians have been killed since the start of the assault, which has also left 41 fighters from the Kurdish forces dead.

Turkey announced on Friday that one soldier had been killed in the fighting.

Seven civilians including a nine-month-old baby were also killed in Turkish border towns in Sanliurfa and Mardin provinces. Nearly 70 other people were injured.