The Latest: IS attacks Iraqi special forces with car bombs

Islamic State militants have unleashed at least four suicide car bombs against Iraqi special forces as they advanced on the militant-held town of Bartella east of Mosul.

One of the car bombs exploded after being shot by a tank. It was not immediately clear if anyone was killed or wounded in the attacks.

Iraqi special forces charged into battle early Thursday, joining a massive operation to retake the IS-held city of Mosul. The fighting is concentrated in largely uninhabited villages on the outskirts of the city.

It's not clear when Iraqi forces will reach the city itself, and the operation is expected to take weeks, if not months.