Three suicide bombers attacked the island of Koulfoua on the Chadian side of Lake Chad on Saturday, killing around 30 people and injuring 80, two security sources told Reuters.
The sources said the attacks coincided with market day. It was not immediately clear who was responsible for the attacks although the swampy maze of islands has previously been targeted by Islamist militant group Boko Haram from neighbouring Nigeria.
Chad extended a state of emergency in the region last month after a double suicide attack that killed 12 people.
Earlier this year, thousands of people fleeing Boko Haram sought refuge on the island although it was not immediately clear if they were still based there.
The deadliest attack on Chad’s side of the lake took place on October 10, another triple suicide, which killed 41 people at Baga Sola, according to N’Djamena.
Since the start of the year, the Chadian army has been on the front line of a regional military operation against Boko Haram, whose attacks have spread from northeast Nigeria, its traditional stronghold, to the country’s three Lake Chad neighbours.
Boko Haram has been hit hard by the offensive, losing territory, but has launched a wave of attacks and bombings in response.
The jihadists, believed to be hiding out in Nigeria’s Sambisa forest and the lake’s many islands, are held responsible for 17,000 deaths and for making 2.5 million people homeless in their six-year campaign of violence.
The UN Office for the Coordination of Humanitarian Affairs said this week that over 50,000 internally displaced people had arrived in the region since end-July.