A triple suicide bombing at a market on an island in Lake Chad on Saturday killed at least 27 people and injured 90 others, said security officials.
The three explosions on Koulfoua were carried out by females, said Chad police spokesman Paul Manga.
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. Nigeria’s Islamic extremist group Boko Haram is suspected, according to Chad’s director general of the gendarmerie, Gen. Banyaman Cossingar.
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.
But as Boko Haram lost territory it stepped up attacks away from its Nigerian strongholds and into remote areas of Chad, as well as neighbouring Niger and Cameroon.
At least 17,000 people, mostly civilians, have been killed since 2009, when the group launched its violent uprising to try to impose Islamist rule in northern Nigeria, according to Amnesty International.