"It's the first time we have lost so many men," President Idriss Deby Itno says, after visiting attack site in Lac province, which borders Niger and Nigeria.
Ninety-two Chadian soldiers have been killed in the deadliest attack ever by Boko Haram militants on armed forces in the country, President Idriss Deby Itno said on Tuesday.
"We lost 92 of our soldiers, non-commissioned officers and officers," in the attack overnight Sunday in Boma, the president said.
"It's the first time we have lost so many men," he added, after visiting the site of the attack in the Lac province, which borders Niger and Nigeria.
The attack on soldiers on the Boma peninsula lasted at least seven hours, and reinforcements sent to help out were also targeted, one soldier told AFP news agency.
He said 24 army vehicles were destroyed, including armoured vehicles, and captured military arms were carried off in speedboats by Boko Haram.
"The enemy has hit at our defences hard in this zone," a senior officer said.
The attack is part of an expanding militant campaign in the vast, marshy Lake Chad area, where the borders of Cameroon, Chad, Niger and Nigeria converge.
Boko Haram launched an insurgency in Nigeria in 2009 before beginning incursions in its neighbouring countries to the east.
Boko Haram has stepped up its attacks in recent months on the islands of the Lake Chad basin.
Boko Haram's insurgency has killed 36,000 people and displaced nearly two million in northeastern Nigeria since it began, according to the UN.