Malian Islamist group MUJAO, which claimed twin car bombings in Niger on Thursday, is an offshoot of Al-Qaeda in the Islamic Maghreb (AQIM) which advocates jihad, or holy war, in West Africa.
The Movement for Oneness and Jihad in West Africa, which became one of the masters of northern Mali before French and African armies intervened in the country in January, has claimed a number of abductions in the northeast of Mali.
It has also been active in neighbouring Algeria where it has also claimed several attacks on Algerian forces.
MUJAO emerged in December 2011 and, until Thursday's double attack on an army base and a French-run uranium mine in northern Niger, had rarely claimed attacks outside the territory of Mali and Algeria.
Around 20 people were killed in Thursday's attacks and several trainee army officers were taken hostage.
However, it had already been active in Niger, claiming the abduction in October 2012 of five of the country's nationals and a Chadian working for aid groups in the south east of the country. The Nigerians were freed, but the Chadian national, shot during the abduction, died of his injuries.
MUJAO came into being on December 10, 2011. On that day it claimed the kidnapping in late October in western Algeria of three European volunteer workers of Spanish and Italian nationality.
The Tuareg separatists of the MNLA group launched an offensive against the government in northern Mali in January 2012 but AQIM, MUJAO and a third Islamist groups -- Ansar Dine -- soon overpowered them.
The Islamist coalition eventually seized control of the entire northern half of the country and Gao -- the largest city in the region -- became MUJAO's main base.
It had made its mark in March 2012 when it abducted the Algerian consul and six members of his mission in Gao.
The group announced the execution of the vice-consul in September, but Algiers never confirmed the report.
MUJAO, AQIM and Ansar Dine, who shared out northern Mali among themselves and have maintained close links, were chased from the region's big towns by the French military, which allied with African troops to take on the Islamists in January of this year.
But they still make their presence felt and MUJAO has claimed several suicide attacks in the regions of Gao, Kidal and Timbuktu.
MUJAO, which also claimed the abduction of one of seven French hostages held in the Sahel, was founded by Mauritanian Hamada Ould Mohamed Kheirou, alias Abou Ghoum-Ghoum.
One of his chiefs is Omar Ould Hamaha, a Malian from the northern town of Kidal, and a former lieutenant of one of the main jihadist chiefs in the Sahel, Algerian Mokhtar Belmokhtar. Belmokhtar, a former member of AQIM, formed a new group called "Signataries in Blood".
MUJAO is considered to be the least ideological of the Islamist groups in the region, but more like a criminal group, living from trafficking.
One of the group's top commanders, Hicham Bilal, quit the group in November, 2012, lambasting its leaders and accusing it of drug smuggling.
Just weeks later, on December 7, MUJAO was added to the UN list of Al Qaeda groups and slapped with sanctions.