US Secretary of State John Kerry has described the attack on Doron Baga and Baga town in Borno state, where several people were killed, as a “crime against humanity”.

“What they have done… is a crime against humanity, nothing less,” Kerry said as satellite images, which suggested massive destruction in the two towns emerged.

Hundreds of people, if not more, are reported to have been killed in attacks on the towns of Baga and Doron Baga on the shores of Lake Chad in Borno state, according to Amnesty International.

Boko Haram was “evil” and a serious threat “not just in Nigeria and the region but to all of our values”, Kerry said during a visit to Bulgaria, where he commented on the recent attack. He said he had spoken earlier to his British counterpart, Philip Hammond — who was also in Sofia — about the possibility of “a special initiative with respect to Nigeria and with respect to Boko Haram”.