The attack on Al Bab, a town held by Turkey-backed opposition fighters, comes days after a Turkish airstrike killed at least 11 Syrian troops and Kurdish fighters
Two Turkish soldiers were killed in an operation against Kurdish fighters in northern Iraq, bringing the total number of Turkish troop deaths to eight this week.
Kurdish forces said militants staged a new attack on the prison Sunday in an attempt to break the security cordon and support inmates who are still in control of parts of the prison, the largest facility in Syria housing ISIS militants.