An Iraqi official says part of a gas facility attacked by militants is still burning.

The mayor of Dibbis, the town where the facility is located near the northern city of Kirkuk, says three attackers were killed Sunday and the situation is now "under control," but firefighters are still trying to extinguish a fire that erupted in the compressor.

Abdula Nouradding says the attack is "not affecting the functioning" of the Dibbis power plant.

There was no immediate claim of responsibility for the attack but the Islamic State group has claimed responsibility for multiple attacks targeting key infrastructure facilities in the past.

After overrunning nearly a third of Iraq in 2014, IS has suffered a string of territorial defeats but still controls the second largest city, Mosul.