Fourteen people were killed and 13 were missing after Boko Haram jihadists attacked a fishing village in western Chad on Tuesday, government officials said.
Violence from the Boko Haram insurgency started in Nigeria a decade ago, but has since spread to neighbouring countries Chad, Niger and Cameroon.
"There were 14 dead, five wounded and 13 missing in the attack" near the village of Kaiga on the shores of Lake Chad, Imouya Souabebe, the prefect of the region, told AFP on Wednesday.
Kaiga lies in marshland in a remote, sprawling region where the borders of the four countries -- Cameroon, Chad, Nigeria and Niger -- meet.
The village is about 60 kilometres (35 miles) from the border with northeast Nigeria, the springboard for Boko Haram raids and kidnappings in neighbouring countries.
"We know that there are always Boko Haram elements moving around the (border) area, so they are behind this attack," Souabebe said.
"The attackers first came in a small group and then brought in reinforcements to attack the fishermen."
The region's governor, Noki Charfadine, gave a toll of at least nine dead.
He said the attack had taken place in a "red zone, where fishing is forbidden."
Boko Haram launched its armed insurgency in northeastern Nigeria -- a campaign that has killed 35,000 people and caused around two million to flee their homes.
The spread of violence to Chad, Cameroon and Niger has prompted the formation of a regional military coalition to fight the jihadists.
Boko Haram has since split in two, with the emergence of a branch allied to the Islamic State (IS) group, known as Islamic State Group in West Africa or ISWAP.
The other faction, loyal to the movement's historic leader, Abubakar Shekau, is known for targeting civilians, including village attacks and suicide attacks.
The ISWAP, which has about 3,000 men grouped at Lake Chad, has been building its capacity and mainly targets the armed forces of countries in the region.
In Chad, four soldiers were killed by jihadists on December 2 in the attack on one of their positions on the shores of the lake. In recent months, many civilians have been killed or abducted in this area as well, mostly in Chad and Cameroon.