At least 30 people have been killed and 80 others injured after a triple suicide bombing on an island in Lake Chad, according to security officials.

Saturday’s blast, in a part of the lake controlled by Chad, has been attributed by local security sources to Boko Haram rebels.

Three insurgents blew themselves up in three different locations across the island, according to the same security source speaking on condition of anonymity.

The latest bombing comes after the Chadian authorities declared a state of emergency in region on Nov. 9 following repeated Boko Haram attacks.

The region is an area most exposed to attacks from Boko Haram, which is active also in Niger, Nigeria and Cameroon.