Seven members of a French family were kidnapped Tuesday in Cameroon near the Nigerian border, an attack French President Francois Hollande said was likely carried out by a Nigerian "terrorist group".
Radical Islamist group Boko Haram has carried out a violent insurgency in northern and central Nigeria for several years, but what is considered its main branch has never claimed the kidnapping of Western hostages.
Here are some facts on a new group called Ansaru, seen as an offshoot of Boko Haram, that has claimed two recent attacks in which expatriates were abducted.
FULL NAME: In emailed statements purportedly from the group, it has identified itself as Jamaatu Ansarul Muslimina Fi Biladissudan, which is Arabic for Vanguard for the Aid of Muslims in Black Africa.
MEMBERSHIP: Little is known about its members. Some experts say its leader may be Khalid al-Barnawi, one of three Nigerian extremists labelled a "global terrorist" by the United States last year.
AIMS: When claiming attacks and kidnappings, it has mentioned France's intervention in Mali and European nations' "atrocities done to the religion of Allah". However, experts do not take such claims at face value and see the group more as a criminal gang with an Islamist strain.
FOREIGN LINKS: The group is believed to have links of some kind with Al-Qaeda in the Islamic Maghreb, Al-Qaeda's north African wing. The US State Department described Barnawi as tied to Boko Haram and with "close links" to AQIM. Its kidnappings would seem to mimic those claimed by AQIM in other countries.
ABDUCTIONS: Ansaru has been mentioned in connection with at least three hostage-takings:
-- The May 12, 2011, abductions of a Briton and an Italian working for a construction firm in Kebbi state, near the border with Niger. The victims were killed on March 8, 2012, in neighbouring Sokoto state during a botched rescue operation.
-- The December 19, 2012, kidnapping of a French engineer in Katsina state, bordering Niger. Ansaru claimed the kidnapping, and the victim's whereabouts remain unknown.
-- The February 16, 2013, kidnapping of seven foreigners from a construction site in Bauchi state. The hostages reportedly include two Lebanese, two Syrians, one Briton, a Greek citizen and an Italian. Ansaru claimed the kidnapping, and the victims' whereabouts remain unknown.
OTHER ATTACKS: Ansaru claimed responsibility for a January 19 attack in central Nigeria that killed two soldiers who were due to be deployed to Mali.