Twenty-four Chadian soldiers were killed in an attack by suspected jihadists in the troubled Lake Chad region, a senior local official said,
"Troops from a returning patrol were resting when they were attacked by Boko Haram," the region's deputy prefect, Haki Djiddi, told AFP.
"Twenty-four troops were killed, several were wounded, and others have scattered into the countryside."
Army spokesman General Azem Bermandoa Agouna confirmed that an attack had taken place at Tchoukou Telia, an island 190 kilometers northwest of the capital N'Djamena, but refused to give any toll.
Lake Chad is a vast area of water and marshland bordered by Niger, Nigeria and Cameroon as well as Chad.
Jihadists from Boko Haram and a rival splinter group, the Islamic State West Africa Province, have been using the region for years as a haven from which to attack troops and civilians.
The Chadian authorities tend to call the jihadists "Boko Haram" regardless of their affiliation.
In March 2020, around 100 Chadian troops were killed in an overnight attack on the lake's Bohoma peninsula, prompting an offensive led by Chad's then president, Idriss Deby Itno.
Deby was killed in April 2021 during fighting against rebels in northern Chad and was succeeded by his son.
Boko Haram launched a revolt in northern Nigeria in 2009 before extending its campaign into neighboring countries.
According to UN figures, more than 36,000 people, most of them in Nigeria, have died and three million have fled their homes.