Three fighters with the so-called Islamic State are said to have stormed a power plant north of Kirkuk, killing 11 people before blowing themselves up, according to Iraqi police.
Kirkuk is about 100 miles from the Islamic State-held city of Mosul, where Iraqi forces are waging a wide-scale offensive to recapture the city.
Major Ahmed Kader Ali said the men entered the facility early on Friday, took 10 workers hostage, and demanded to be taken to two Iranians who worked there.
One of the workers reportedly led the fighters to the Iranians before escaping, while the fighters killed the Iranians and other workers and then blew themselves up as the police arrived.
A US bomb disposal expert has died from wounds he sustained from a roadside bomb planted near the city of Mosul.
The service member, who has not been identified, had been operating as an explosive ordnance disposal specialist in support of the Iraqi Kurdish force known as the peshmerga.
About 5,000 US forces are in Iraq, with more than 100 of them embedded with Iraqi and Kurdish Peshmerga forces involved with the Mosul offensive.
This is the fourth US soldier to have been killed since the start of Operation Inherent Resolve in 2014.
ITV News has witnessed first-hand the ferocious battle for Mosul travelling with Iraqi special forces as they came under constant attack.Read the full story ›
More than 5,500 people have been forced to flee their homes because of fighting around the Iraqi city of Mosul since Monday, the International Organisation for Migration has said.
It added that most of 5,640 people displaced have fled in the last 24 hours.
Earlier on Thursday, the Iraqi prime minister said the offensive to reclaim the IS-held city is "moving more quickly" than expected.
An offensive to reclaim Mosul from so-called Islamic State militants is "moving more quickly" than expected, the Iraqi prime minister has said.
In a video conference call, Haider al-Abadi told officials in Paris that the cooperation of Iraqi forces and the Kurdish Peshmerga fighters showed that Iraq was "united" in its aim to defeat the extremist group.
The forces are pushing towards the town more quickly than we thought and more quickly than we had programmed in our campaign plan.
French President François Hollande, who hosted a meeting to discuss the future of the city, added there was evidence that Islamic State fighters were already fleeing Mosul for Raqqa, the group's stronghold in Syria - and warned that "everything should be done" to stop them from regrouping there.
ITV News cameras have travelled with the army during the operation, which is expected to lead to the biggest battle in Iraq since the US-led invasion in 2003.
ITV News cameras have travelled with the Iraqi army, as they free villages held captive by IS in the battle for Mosul.Read the full story ›
ITV News has seen "dozens of landmines and various amounts of ammunition" left by retreating so-called Islamic State militants as the Iraqi Army battle to reach Mosul.
News Editor Lufti Abu Aun says the Army's 9th Division claimed to have liberated 10 villages southwest of the city - including Ibrahim al Khalil and Adla - where they came across the weapons cache.
Lufti Abu Aun recorded a video of the ITV News team in an Iraqi army humvee driving to the liberated villages.
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Peshmerga forces and Iraqi troops launched an offensive against the so-called Islamic State on Monday.Read the full story ›
Kurdish forces have advanced further towards Mosul as they prepared to reclaim the Iraqi city they were forced out of by IS in 2014.Read the full story ›
The jihadist group released a propaganda video showing people apparently enjoying life, shopping for food and eating in restaurants.Read the full story ›