Boko Haram leader Abubakar Shekau releases a video pledging to continue attacks

The soldiers were attacked on Monday on the island village of Boma in the swampy Lake Chad zone in the west of the country, where the armies of Chad, Nigeria and Niger have been fighting the Islamist militants for years. "I have taken part in many operations ... but never in our history have we lost so many men at one time," Deby said during a visit to the site on Tuesday

N'DJAMENA: Boko Haram militants killed 92 Chadian soldiers and wounded 47 more in the deadliest attack ever on the country's military, President Idriss Deby said late on Tuesday.

The soldiers were attacked on Monday on the island village of Boma in the swampy Lake Chad zone in the west of the country, where the armies of Chad, Nigeria and Niger have been fighting the Islamist militants for years.

"I have taken part in many operations ... but never in our history have we lost so many men at one time," Deby said during a visit to the site on Tuesday.

Footage on state TV showed Deby, who has ruled Chad since 1990 and survived several rebellions and coup attempts, walking among the charred remains of burned-out vehicles.

The Boko Haram insurgency, which erupted in northeast Nigeria in 2009, has killed more than 30,000 people and forced about 2 million to leave their homes.

Further afield in Mali, Burkina Faso and western Niger, al Qaeda and Islamic State-linked militants are expanding their presence and have killed hundreds of troops over the last six months.