At least six civilians have been killed, 15 others injured during a firefight between Iraqi troops and peshmerga in the town of Altun Kupri in northern Iraq's disputed Kirkuk province.

The peshmerga reportedly launched an attack after Iraqi government forces seized control of the town.

Victims of the attack told Anadolu Agency that the peshmerga used Katyusha rockets, targeting civilians in Altun Kupri.

Meanwhile, Associated Press reported that it was unclear if there were other casualties, adding that the town was mostly empty as most of its 9,000 residents fled the fighting.

Iraqi forces are seeking to re-establish Baghdad's authority over territory captured by the peshmerga forces outside the official boundaries controlled by the Kurdistan Regional Government (KRG) during the course of war against Daesh militants.

The peshmerga had moved into Kirkuk after the Iraqi army fled the region in the face of Daesh's advance in 2014. The KRG move prevented Kirkuk's oilfields from falling into the hands of the militants.

Altun Kupri marks the administrative limit between Kirkuk and Irbil. It belongs administratively to the Kirkuk province.