A suicide bomber killed five people, including a Chadian soldier, when she blew herself up on the shores of Lake Chad, military and government sources said.
The sources said the attack happened shortly after midnight in the compound of a traditional chieftain in the Kaiga-Kindjiria district. The attacker walked in and detonated her bomb as people in the compound were preparing for bed, they said, without giving further details.
Lake Chad, which sprawls across Nigeria, Niger, Chad and Cameroon, is a stronghold for the two main factions of Nigerian Islamist militant group Boko Haram: Boko Haram itself and the Islamic State in West Africa Province (ISWAP) splinter group.
Violence in the region has killed more than 30,000 people and displaced about two million since 2009, when Boko Haram first launched an uprising with the intention of carving out an Islamic caliphate in north-east Nigeria.
Jihadists in the Lake Chad region routinely ambush soldiers, open fire on markets and kidnap women and children, including nearly 270 schoolgirls in Chibok in 2014, a hundred of who are still missing.
In June, West African troops killed 42 suspected Islamic State fighters in a battle in the Lake Chad region, the heaviest death toll suffered by the insurgents in the past six months.
They continue to show themselves capable of devastating hit-and-run attacks. Last month, an attack by suspected Islamists on a group returning from a funeral in Nigeria’s north-eastern Borno state killed at least 65 people.