Gunmen believed to be members of Islamist group Boko Haram burned down a police station in volatile northeast Nigeria, killing two policemen and a civilian, the military said Monday.

A senior army officer with the military joint task force (JTF) deployed in the area, who asked not to be named, said gunmen stormed Mafa police station in Borno state on Saturday night.

"Two policemen and one civilian were killed in the attack," he said, adding that troops had been drafted in.

The JTF Sunday raided a suspected Boko Haram base in London Ciki, Maiduguri, killing two Islamists, the officer also said.

"Two locally made pistols were recovered and five suspects were arrested as a result of the operation," he added.

Troops have recently stepped up raids on suspected Boko Haram hideouts, looking for explosives and arms.

Maiduguri, the home base of Boko Haram, has seen some of the worst violence blamed on the extremist sect, which has focused its attacks on the mainly Muslim north.

Police, security agents and government offices have been targetted in the violence. Churches have also be attacked as dozens of Christian worshippers have been killed in recent months.

Boko Haram's increasingly bloody insurgency has claimed more than 1,000 lives since mid-2009.

Nigeria's 160 million people are roughly divided between a mainly Muslim north and predominantly Christian south.