Authorities in northern Cameroon say a local self-defense group used a poisoned arrow to kill a woman with explosives strapped to her body.

Midjiyawa Bakary, the governor of Cameroon’s Far North region, said Wednesday that the 40-year-old woman had crossed over from neighboring Nigeria along with a 14-year-old girl.

Local residents shot the poisoned arrow at the woman after she failed to stop as demanded. The girl also died when she detonated her own explosives.

Residents near the northern town of Mora said at least five other suicide bombers have died in the last several days.

The attacks were reported shortly before Cameroon’s president Paul Biya left for Nigeria to discuss ways of ending Boko Haram violence with his Nigerian counterpart.