Rebel fighters as they advanced towards the Islamic State-held city of al-Bab Credit: Reuters
A “chemical gas” rocket attack struck Syrian rebels as they attempted to take back their city from the so-called Islamic State.

Around 22 Turkey-backed fighters in IS-controlled town al-Bab showed symptoms of “chemical gas injuries”, a Turkish military spokesperson said.

Al-Bab is a major target in the “Euphrates Shield” operation to push the jihadists away from the Syrian side of the Turkish border.

The rocket attack was in Syria’s Haliliye area, according to state-run Anadolu agency.

It did not specify when the attack occurred.

Turkish AFAD emergency relief teams had conducted various tests on the affected rebels for traces of chemical materials at a hospital in Turkey’s border province of Kilis.