27 people has been killed by three suicide attacks in an island on Lake Chad, security sources have said.
The blasts, on the island of Koulfoua on the Chadian side of the lake, struck a weekly market, the sources said.
No group has said it was behind the attacks, but the region is under a state of emergency after attacks by the Boko Haram militant group.
This year thousands of people fleeing the Islamist fighters sought safety on the island.
Chad has played a key role helping Nigeria recapture areas seized by the group in northern Nigeria.