A sustained gun battle broke out between Nigerian security forces and suspected Islamist militants in the northern city of Damaturu on Thursday, and several explosions were heard, witnesses and the local police commissioner said.

Confrontations between security forces and the violent Boko Haram sect have become increasingly frequent in the past couple of weeks, as the north's simmering conflict escalates, though the insurgency remains low level and sporadic.

Nigerian police arrested 14 suspected members of Boko Haram and seized explosives after a gun battle left four militants and three policemen dead in the city of Kano over the weekend.

Yobe state police commissioner Lawan Tanko said fighting broke out after his men raided a suspected Boko Haram hideout.

There was exchange of gunfire between my men and members of Boko Haram this evening and several bomb blasts. We attacked them in their hideout outside the state capital city centre, he told Reuters by telephone.

I know we killed some of them. I cannot say the number because it is night. But the situation is under control.

Damaturu was the scene of the most deadly Boko Haram assault to date, when 65 people were killed in a wave of shootings and bombings on November 5 that left churches, police stations and mosques reduced to smouldering rubble.

Describing the latest flare-up of fighting there, witness Jibo Usman, 45, a Damaturu resident, said he heard the shootings and bombings late in the evening.

We are under siege, he said. Bomb blasts and gun shots are raining down on us non-stop. Everybody is indoors ... We are in a terrible situation.

Boko Haram, whose name roughly translates as Western learning is forbidden has been blamed for scores of shootings and bombings in the north, including a spate of attacks in the past few weeks across the region.

Despite many crackdowns, Nigerian security forces have so far been unable to contain Boko Haram violence. This year the group struck in the capital Abuja twice, including a suicide car bomb attack against the U.N. headquarters that killed 26 people.

(Reporting by Mike Oboh; Writing by Tim Cocks; Editing by Louise Ireland)