Three female suicide bombers have blown themselves up at a market in Chad, killing at least 27 people.
Boko Haram is suspected of orchestrating the blasts on Koulfoua Island in Lake Chad, which borders Nigeria, Cameroon, Niger and Chad.
Security officials told the Associated Press that at least 90 people were injured in Saturday’s attack, carried out by three women.
General Banyaman Cossingar, the director general of Chad’s national police, said there had been no official claim of responsibility but Boko Haram was suspected.
The terrorist group has carried out several bombings and massacres in the region, causing the government to impose a state of emergency last month.
Thousands of refugees have been fleeing to Lake Chad in recent months in efforts to escape the Boko Haram’s violent insurgency in Nigeria.
A report by the UN’s refugee agency described people arriving in canoes and boats, including many who had survived massacres that killed their families and friends.
But they arrived to become the targets of yet more attacks, with previous suicide bombings targeting fish markets and refugee camps.
Chadian military forces have helped Nigeria push the Islamist group back and re-capture swathes of territory but militants have now pushed into neighbouring countries to launch more attacks.
The rise of Boko Haram
The rise of Boko Haram
1/19 Boko Haram
The leader of the Islamist extremist group Boko Haram Abubakar Shekau delivers a message. Boko Haram has claimed responsibility for the mass killings in the north-east Nigerian town of Baga in a video where he warned the massacre “was just the tip of the iceberg”. As many as 2,000 civilians were killed and 3,700 homes and business were destroyed in the 3 January 2015 attack on the town near Nigeria's border with Cameroon
2/19 Boko Haram
People displaced as a result of Boko Haram attacks in the northeast region of Nigeria, are seen near their tents at a faith-based camp for internally displaced people (IDP) in Yola, Adamawa State. Boko Haram says it is building an Islamic state that will revive the glory days of northern Nigeria's medieval Muslim empires, but for those in its territory life is a litany of killings, kidnappings, hunger and economic collapse
3/19 Boko Haram
Nitsch Eberhard Robert, a German citizen abducted and held hostage by suspected Boko Haram militants, is seen as he arrives at the Yaounde Nsimalen International airport after his release in Yaounde, Cameroon on 21 January 2015
4/19 Boko Haram
Officials of the Nigerian National Emergency Management Agency (NEMA) visit victims of a bomb blast in Gombe at the Specialist Hospital in Gombe. According to local reports at least six people were killed and 11 wounded after a bomb blast in a marketplace in Nigeria's northeastern state of Gombe on 16 January 2015. Islamist militant group Boko Haram has been blamed for a string of recent attacks in the North East of Nigeria
5/19 Boko Haram
People gather at the site of a bomb explosion in a area know to be targeted by the militant group Boko Haram in Kano on 28 November 2014
6/19 Boko Haram
People gather to look at a burnt vehicle following a bomb explosion that rocked the busiest roundabout near the crowded Market in Maiduguri, Borno State on 1 July 2014. A truck exploded in a huge fireball killing at least 15 people in the northeast Nigerian city of Maiduguri, the city repeatedly hit by Boko Haram Islamists
7/19 Boko Haram
President Goodluck Jonathan visits Nigerian Army soldiers fighting Boko Haram
8/19 Boko Haram
Displaced people from Baga listen to Goodluck Jonathan after the Boko Haram killings
9/19 Boko Haram
Nigeria's President Goodluck Jonathan speaking to troops during a visit to Maiduguri, the capital of Borno State; most of the region has been overrun by Boko Haram
10/19 Boko Haram
Members of the Nigerian military patrolling in Maiduguri, North East Nigeria, close to the scene of attacks by Boko Haram
11/19 Boko Haram
Boko Haram’s leader, Abubakar Shekau, appears in a video in which he warns Cameroon it faces the same fate as Nigeria
12/19 Boko Haram
South Africans protest in solidarity against the abduction of hundreds of schoolgirls in Nigeria by the Muslim extremist group Boko Haram and what protesters said was the failure of the Nigerian government and international community to rescue them, during a march to the Nigerian Consulate in Johannesburg
13/19 Boko Haram
Boko Haram militants have seized the town in north-eastern Nigeria that nearly 300 schoolgirls were kidnapped from in April 2014
14/19 Boko Haram
A soldier stands guard in front of burnt buses after an attack in Abuja. Twin blasts at a bus station packed with morning commuters on the outskirts of Nigeria's capital killed dozens of people, in what appeared to be the latest attack by Boko Haram Islamists, April 2014
15/19 Boko Haram
The aftermath of the attack, when Boko Haram fighters in trucks painted in military colours killed 51 people in Konduga in February 2014
16/19 Boko Haram
The leader of Boko Haram, Abubakar Shekau (with papers) in a video grab taken in July 2014
17/19 Boko Haram
Ruins of burnt out houses in the north-eastern settlement of Baga, pictured after Boko Haram attacks in 2013
18/19 Boko Haram
A Boko Haram attack in Nigeria, 2013
19/19 Boko Haram
Abubakar Shekau, Boko Haram’s leader
The death penalty was re-introduced in Chad for terror offences in response to bombings in the summer.
Authorities executed 10 alleged members of Boko Haram by firing squad in August after they were accused of involvement on twin attacks in N'Djamena that killed 38 people.
At least 17,000 people, mostly civilians, have been killed since Boko Haram launched its bloody campaign to establish an Islamist state in northern Nigeria, according to an estimate by Amnesty International.
The group pledged allegiance to Isis in March and now calls itself the “West African province” of the so-called Islamic State.