The bodies of 42 fishermen kidnapped by Boko Haram last week have been recovered from Lake Chad, the Cameroonian military said late Monday.

The group attacked Darak, a village on the Nigeria-Cameroon border, on June 8 and grabbed the fishermen, having killed 10 fishermen in the nearby Cameroonian village of Touboun Ali two days earlier.

"Cameroonian sailors and villagers… saw several bodies floating on the water and immediately alerted security forces," Col. Nomo Jean Claude said. "We recovered 42 bodies from the water between Saturday and Sunday.

"After identification, we found they were of Cameroonian, Nigerian and Chadian nationality. The bodies were immediately handed over to the families for burial."

Boko Haram, which has been fighting an insurgency in northern Nigeria since 2009, has intensified its attacks in the Lake Chad region since the beginning of the month.

An attack on Bosso in Niger on June 3 killed 26 soldiers and more than 50,000 people have fled the border region between Nigeria and Chad.

Niger and Chad have said they will send troops to Nigeria's Borno state to fight the extremists. The three countries, along with Cameroon and Benin, are part of a multinational force committed to fighting Boko Haram, who have killed at least 20,000 people and displaced 2.7 million in seven years.