After a deadly attack there by Boko Haram militants last week, A regional governor in southern Niger ordered the evacuation of the West African nation's inhabited islands on Lake Chad.

A regional governor in southern Niger on Thursday ordered the evacuation of the West African nation's inhabited islands on Lake Chad following a deadly attack there by Boko Haram militants last week.

At least 74 Nigerien soldiers and civilians were killed when hundreds of the militants aboard motorised canoes attacked the island of Karamga at dawn on April 25.

Dozens of soldier are still missing following clashes that ultimately drove out the attackers, leaving 156 of them dead.

Residents were told to leave the islands by May 4, according to a statement released by the governor of the region of Diffa.

"Due to security imperatives, the governor of the region of Diffa has the honor of inviting the populations living on the islands in the Nigerien part of Lake Chad to leave the islands and rejoin the mainland," the statement read.

Karamga, attacked once before by Boko Haram in February, is prized by both sides as a strategic base among a vast maze of waterways and swampland straddling the borders between Niger, Chad, Nigeria and Cameroon.

The attack occurred despite significant military victories by the four countries in winning back territory from Boko Haram in northern Nigeria.

Nigeria's military has rescued hundreds of women and children who had been kidnapped by Boko Haram militia and were being detained in Sambisa Forest where the army is attempting defeat the Islamist group in one of its final strongholds.

Reuters