The group has claimed responsibility for some daring attacks in Nigeria.
Last Monday, Ansaru, a hitherto little-known sect stunned the international community when it announced responsibility for the kidnap of seven foreigners in Bauchi, North-East Nigeria.
Here are five quick things you need to know about the group.
Started: Ansaru was formed in January 2012. It announced its presence through a video, released in January 2012.
Identity/Agenda: Its full name (in Arabic) is Jama'atu Ansarul Muslimina Fi Bidalis Sudan. This translates to "Vanguards for the Protection of Muslims in Black Africa."
The group claims it is fighting to reclaim "the lost dignity of Muslims of black Africa" and to create an Islamic caliphate covering Niger Republic, Cameroon, and Northern Nigeria.
Analysts suspect Ansaru is an offshoot of Boko Haram. But the new group appears to have a different agenda from Boko Haram. So far, Ansaru activities portray a wider regional agenda. The group argues that violence should be unleashed only in "defence" of Muslims.
Some analysts suggest the group is more sophisticated than Boko Haram and would rely more on targeted attacks since it is opposed to Boko Haram's tactics which has resulted in thousands of civilian deaths, including Muslims.
Leadership: In December, French journal, Jeune Afrique-L'Intelligent, said Ansaru was led by a little-known Abu Ussamata al-Ansary.
Some experts say Abu Ussamata al-Ansary is a nickname for perhaps, Khalid al-Barnawi - one of the purported three Nigerian Islamic fighters' tagged "global terrorist" by the United States in 2012. The U.S. State Department suspects Barnawi has "close links to Al-Qaeda in the Islamic Maghreb", and tied to Boko Haram.
Strategy: It does appear Ansaru specializes in taking foreigners hostage. In its short lifespan, Ansaru has proved to be a lethal threat, using dynamite to penetrate heavily-fortified compounds and taking foreigners hostage.
The U.K. government blamed Ansaru for taking a Briton and an Italian hostage in early 2012 - shortly after announcing its presence - in Sokoto, North-West Nigeria.
In December 2012, the group is believed to have abducted French national, Francis Colump, 63, following an attack on a well-guarded compound in the northern town of Rimi in Katsina, North-West Nigeria.
In January, Ansaru said it carried out an attack that killed two Nigerian soldiers as they prepared to deploy to Mali. The group said it attacked the troops because the Nigerian military was joining the French-led military campaign to "demolish the Islamic empire of Mali".
Last Sunday, Ansaru took responsibility for the abduction of seven European and Middle Eastern nationals from a compound owned by the Lebanese construction company, Setraco, in Bauchi State, North-East Nigeria.
Ansaru said the kidnap was to avenge "transgressions" by European nations in Mali and Afghanistan, where Western forces are battling Islamist insurgents. The hostages are yet to be found.
International outlook: In its short existence, the sect has managed to attract international attention, due to its strategy. The sect is listed by the U.K. government as a "terrorist organisation" aligned with al-Qaeda in the Islamic Maghreb, AQIM. United States' intelligence also suggests Ansaru has strong ties with AQIM.