IS militants attack Iraqi city of Kirkuk as Mosul offensive continues
Iraqi media reported that suicide bombers had attacked police stations and a power station, but that security forces had repelled the assaults.
A news agency affiliated to IS claimed its fighters had broken into Kirkuk's town hall and seized a central hotel.
The attacks come as Iraqi pro-government forces continue an offensive to retake IS-held Mosul, to the north.
IS militants were reported to have set fire to a chemical plant south of Mosul as they retreated on Thursday.
Sources said they started the fire at the sulphur plant in al-Mishraq deliberately when they were being pushed out of the area by security forces.
Dawn attack
There are conflicting reports about the scale and extent of the attack on Kirkuk.
A local TV channel broadcast footage of black smoke rising over the city, with automatic gunfire audible.
The Beirut-based newspaper al-Sumaria reported that during the dawn attack, three suicide bombers had blown themselves up.
A district police chief, Brig Gen Sarhad Qadir, told the BBC that militants and a number of suicide bombers had attacked Kirkuk's emergency police building, an old police directorate building, another police station, a political party headquarters and a power station in nearby Dibis that was still under construction.
"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.
Kirkuk police sources said three Iranian workers at the power station were killed, along with eight Iraqis.
Kirkuk's governor, Najm al-Din Karim, told the Kurdish news agency, Rudaw, that Kurdish Peshmerga and counter-terrorism forces were completely in control of the situation, and said the attackers were from IS sleeper cells.
Security forces had killed six suicide bombers, Mr Karim added.
A security source meanwhile told the BBC there were ongoing clashes between IS militants and Peshmerga in the south and south-west of Kirkuk.
Kirkuk, a multi-ethnic city that is located about 180 miles (290km) north of the capital Baghdad and 105 miles (170km) south-east of Mosul. It is claimed both by Iraq's central government and by the country's Kurds.
Source: bbc.com