Militants on Wednesday killed a policeman before blowing up two oil wells in Kirkuk, a northern province claimed by both Iraq's federal government and the Kurds, officials said.
A security official told AFP that "ISIS assailants" killed a policeman and "wounded two others."
The attackers then "blew up wells 177 and 183 at the Bay Hassan field," the oil ministry said in a statement.
The first fire was "brought under control in record time", but "firemen are still active at the second" well several hours after the attack, the ministry added.
Iraqi Kurdish peshmerga forces took control of Kirkuk, home to key oilfields including Bay Hassan, in June 2014 after federal forces withdrew in the face of an ISIS offensive.
In late 2017, Baghdad officially claimed victory against ISIS, after a grinding military campaign supported by a US-led coalition.
But the Kurds -- who run an autonomous government in Erbil -- and the federal government dispute ownership of Kirkuk's lucrative oilfields.
ISIS maintains an ability to perpetrate attacks, operating mainly at night and often exploiting the discord between Baghdad and Erbil.
