A Chadian military spokesman said on Friday that four of the country’s soldiers were killed in clashes with Boko Haram fighters on an island in Lake Chad.
He reported that 33 Boko Haram fighters were also killed in the clashes.
"Boko Haram elements on Wednesday attacked our forces in Choua,” Colonel Azem Bermandoa Agouna told the AFP news agency.
"The Chadian army violently repelled the attack. We killed 33 Boko Haram members and recovered several light arms and anti-tank grenades. We regret the loss of four soldiers and also recorded four wounded."
Boko Haram has been fighting a six-year insurgency in a bid to establish a state of its own in northern Nigeria and other neighbouring territories, including areas surrounding Lake Chad. In the process it has killed thousands of people and caused about 1.5 million to flee their homes.
A recent offensive by Nigerian army was backed by neighbouring Niger and Chad, leading to the recapture of most of the territory in Adamawa, Borno and Yobe states and forcing Boko Haram to retreat and seek other areas to capture.