BAGHDAD — Officials say a senior Kurdish military commander and eight Kurdish fighters have been killed in clashes with Islamic State militants in northern Iraq.

Brig. Khatab Omar says Brig. Gen. Shirko Fatih was killed as he was leading Kurdish peshmerga troops in a battle against IS extremists early on Friday outside the city of Kirkuk.

He says at least eight Kurdish fighters were killed during the clashes.

Omar says IS militants attacked the peshmerga fighters' positions south of Kirkuk, which is located 290 kilometers (180 miles) north of Baghdad.

The casualties come as Iraq is facing its worst crisis since the 2011 withdrawal of U.S. troops, with Islamic State militants now in control of about a third of the country.