Early on Friday morning, ISIS launched a major counter-offensive on the city of Kirkuk in retaliation for Iraqi and Kurdish forces assault around Mosul that started earlier this week in Iraq.
The Islamic State's assault on Kirkuk, which lies in an oil- producing region, killed 18 members of the security forces and workers at a power station outside the city, including two Iranians, according to Reuters.
Hours after the initial assault, witnesses in Kirkuk said gunfire and explosions could still be heard and ISIS fighters were walking through the downtown district.
District police chief Brig Gen Sarhad Qadir said that suicide bombers had attacked three police buildings and the headquarters of a political party.
"All of the militants who attacked the police emergency building and the old building of the Kirkuk police directorate have been killed but a number of other militants are still in Dumez district," he said.
ISIS also cut the road between the city and the power station 20 miles to the north.
"Because of the ongoing Mosul offensive, they may want to create a situation where forces would be withdrawn from there and the focus shifted to Kirkuk," Mr Karim told Kurdish news agency Rudaw. "Also because they are being defeated in Mosul, they want to boost their morale with these kinds of actions."