KANO, Nigeria: Nigerian soldiers on Sunday killed about 30 suspected members of the Islamic group Boko Haram, including a close associate of the group's leader during a gun battle in northeastern Yobe state, an army spokesman said.

"About thirty suspected Boko Haram terrorists were killed in the battle which lasted several hours," army spokesman Lieutenant Eli Lazarus said in a statement.

"In the battle, the notorious, one-eyed Bakaka, the field commander of Boko Haram in Damaturu and a close associate of Abubakar Shekau was killed," he added.

Troops of the Joint Task Force "engaged in a gun battle with the suspected terrorists" during a search and cordon operation on Boko Haram's hideout in Kandahar and around the cemeteries of Damaturu, the state capital, the statement said.

Ten suspected members of the group arrested during the raid are helping investigators to track other senior members of the group, added the statement.

Six rifles, 90 rounds of ammunition, several telephone sets were recovered during the raid. Knives, bows, arrows, daggers and three cans of Improvised Explosive Device, which were detonated, were also confiscated, Lazarus said.

Yobe state police boss, Patrick Egbuniwe, said earlier Sunday that troops shot dead four suspected members of the Islamist group following a raid on their hideout in Kandahar.

Islamist extremists have been blamed for more than 1,400 deaths since 2010 as part of their insurgency in northern and central Nigeria.