Nigeria's armed forces on Wednesday said it had rescued 338 people held captive by Boko Haram and raided a number of the Islamist militant group's camps on the edge of its stronghold in the northeast's Sambisa forest.

The army said troops carried out a successful raid on camps on Tuesday at the northeastern villages of Bulajilin and Manawashe, along Bita and Damboa road. Reuters was unable to independently verify the details of the military statement.

"The rescued persons which comprised eight males, 138 females and 192 children, have since been evacuated," said military spokesman Sani Usman, adding that 30 suspected militants had been killed.

Suspected members of the militant group, which has killed thousands and displaced 2.1 million people in the remote northeast of Africa's most populous nation, claimed the lives of at least 37 people and wounded 107 others last week in Adamawa and Borno states.

The vast Sambisa forest reserve, the group's remaining stronghold, has become hard to penetrate due to widespread landmines laid by the militant group.

In the last few months the military has ramped up its offensive into the Sambisa and surrounding areas with air strikes and an increase in ground troops.

Security sources in neighboring Niger on Wednesday blamed Boko Haram for the deaths of at least 14 people in an overnight attack on a village in the southeast of the country.

(Reporting by Isaac Abrak; Writing by Alexis Akwagyiram; Editing by Richard Balmforth)