A member of the Kurdish security forces checks his weapon after previous clashes with Islamic State militants on the outskirts of Kirkuk.

The Islamic State of Iraq and Syria (ISIS) Islamist group killed a senior Kurdish commander and five other fighters on Friday in a major attack in Iraq’s Kirkuk province, an officer and a doctor said.

The ISIS assault on areas south and west of the northern city of Kirkuk began at around midnight, sparking fighting with medium and heavy weapons that was still ongoing Friday morning, a police brigadier general said.

Brigadier General Shirko Rauf and five other members of the Kurdish peshmerga forces were killed in clashes, while 46 more were wounded, the police officer and a doctor said.

The Kirkuk province security committee announced a curfew beginning at 10:00 am (0700 GMT) on Friday, saying it will be in effect until further notice.

ISIS spearheaded a sweeping offensive that has overrun much of Iraq’s Sunni Arab heartland since June, presenting both an opportunity for territorial expansion and a threat to the country’s three-province autonomous Kurdish region.

Several Iraqi divisions collapsed in the early days of the offensive, clearing the way for the Kurds to take control of a swathe of disputed northern territory that they have long wanted to incorporate into their region over Baghdad’s objections.

But after driving south towards Baghdad, ISIS turned its attention to the Kurds, pushing them back towards their regional capital Erbil in a move that helped spark U.S. strikes against the jihadists.

Backed by the strikes as well as international advisers and trainers, Kurdish forces have clawed back significant ground from ISIS.

The conflict is redrawing some of the de facto internal boundaries of Iraq in favor of broader Kurdish control in the north.

[wpResize]