Numerous Chad troops have been killed in a clash with jihadists in the Lake Chad region, the latest such incident in the central African nation, officials said on Sunday.

"I present my sincere condolences to the families of the martyrs who fell defending the homeland during this clash and I wish a speedy recovery to the wounded", President Mahamat Idriss Deby Itno said in a post on Facebook, without providing any other details.

The clash was the latest since late October when an attack by Boko Haram jihadists on a Chadian military base killed at least 40 people. In response, the army launched an operation against the militants.

In a statement, the army chief of staff said on Saturday that there was a clash during the day and after several hours "numerous terrorist elements were neutralised" and that a toll would be published later.

According to military sources, the fighting took place in the afternoon on the Karia island, in the northwest of the Lake Chad region.

Several local media published what they said were lists of the troops killed and wounded.

"Numerous high-ranking officers fell", an officer at the chief of staff office told AFP on condition of anonymity.

In a vast expanse of water and swamps, the Lake Chad region's countless islets serve as hideouts for jihadist groups, such as Boko Haram and its offshoot Islamic State in West Africa (ISWAP), who carry out regular attacks on the country's army and civilians.

Boko Haram launched an insurgency in Nigeria in 2009, leaving more than 40,000 people dead and displacing two million, and the organisation has since spread to neighbouring countries.