At least four police officers were killed in Nigeria's northeast Borno state after a gun battle with suspected Islamist insurgents, a police spokesperson said on Saturday.

Borno has been the heartland of an insurgency by Boko Haram and splinter outfit Islamist State West Africa Province (ISWAP) for more than a decade in the northeast, where they continue to carry out deadly attacks against civilian and security targets.

Borno state police spokesperson Nahum Daso Kenneth said the militants had on Friday night attacked Gajiram town in the Nganzai local government area, some 82 kilometres (51 miles) from Maiduguri, the state capital.

"Our men engaged them in a gun battle (and) they denied the terrorists access to the town, and repelled the attack. Unfortunately, four policemen have paid a supreme price," Kenneth said, adding that calm had returned to the town.

ISWAP fighters are known to operate in Nganzai, where they carry out sporadic attacks against security forces and residents.

Nigeria is grappling with widespread insecurity, including armed bandits who kidnap for ransom in the northwest, deadly farmer-herder clashes in the central belt and separatist and gang violence in the southeast.

Reuters