The Nigerian militant group Boko Haram has been in the headlines after it kidnapped nearly 300 schoolgirls in the country's volatile north in recent weeks, and threatened to sell them as slaves.
The kidnappings took place in separate incidents, the largest in April, when more than 300 schoolgirls were seized , of which 276 remain in captivity, according to Nigerian police. This week a further 11 girls were kidnapped in Borno state, where Boko Haram has waged an Islamist uprising for the past five years.
The kidnappings have led to an international outcry and pledges of assistance from various countries, and a $300,000 reward for information from the Nigerian government.
Who Is Boko Haram?
Boko Haram is an Islamist militant group based in northern Nigeria. The extremist group is fighting to overthrow the government and create an Islamic state. It has wreaked havoc in the country through a deadly campaign of bombings, assassinations, and mass abductions.
Boko Haram's official name is Jama'atu Ahlis Sunna Lidda'awati wal-Jihad -- which in Arabic means "People Committed to the Propagation of the Prophet's Teachings and Jihad." But it is widely known as Boko Haram, which loosely means "Western education is forbidden" in the local Hausa language.
The group is based in the northeast city of Maiduguri, the capital of the northeastern state of Borno. It has some support in Nigeria's impoverished Muslim north, particularly in rural areas.
The group's fundamentalist interpretation of Islam makes it "haram," or forbidden, for Muslims to participate in any social, political, and educational activity linked with the West. That includes taking part in elections, receiving a secular education, and wearing Western clothes. That has led some to label the group the "Nigerian Taliban."
What Are The Group's Origins?
Mohammad Yusuf, a charismatic Islamic cleric, formed Boko Haram in Maiduguri in 2002. Yusuf led a group of radical Islamist youth in the 1990s. He was originally interested in education, building a mosque and a madrasah where poor Muslim families enrolled their children.
He did not aim to violently overthrow the government. Instead, he blamed the country's problems on Western values imposed by Nigeria's former British colonial rulers and preached a doctrine of withdrawal from government rule.
Things came to a head in 2009, when police clamped down on the group for its refusal to observe a law making motorcycle helmets mandatory. It led to clashes between Boko Haram supporters and the security services. More than 800 people were killed, including hundreds of Boko Haram supporters. Police captured the group's headquarters and took Yusuf into custody, where he died.
Since then, Boko Haram has carried out a series of deadly attacks targeting security institutions, churches, schools, and the indiscriminate killing of civilians.
Nigerian schoolgirls take part in a rally calling for the release of the missing girls at the state government house in Lagos on May 5.
Yusuf's right-hand man, Abubakar Shekau, took his place and the group changed direction. Without its charismatic founder, the group went underground and became increasingly splintered. Various factions emerged, including in neighboring Niger and Cameroon.
"From 2009, the group changed its dynamic," says Sola Tayo, an associate fellow at the London-based Chatham House. "The violence they have used has become more and more audacious. They're becoming a lot bolder, their armories are becoming more sophisticated, and their tactics have become more blatant as well."
Who Has It Targeted?
Boko Haram has been blamed for the deaths of almost 3,000 people since 2009. Amnesty International estimates that the group was responsible for the deaths of more than 1,500 people this year alone.
The group has targeted Nigerian security forces, members of the country's Christian community, and Muslim leaders and clerics accused of cooperating with the government. It has also targeted foreigners and tourists, albeit on a smaller scale. Among its most audacious attacks was on the UN headquarters in the capital, Abuja, that killed more than 20 people in 2011.
Then, last month, the group kidnapped nearly 300 schoolgirls, of which 53 have since escaped, in the town of Chibok in Borno state. On May 4, another 11 schoolgirls were kidnapped. In a chilling video released on May 5, Shekau threatened to sell the schoolgirls as slaves and force them into marriage.
Is It Linked To Al-Qaeda?
The United States, which has designated Boko Haram as a terrorist organization, has said the group may have ties to Al-Qaeda via the Islamic Maghreb, which operates in northwest Africa; the Al-Shabab extremist group, in Somalia; and Al-Qaeda in the Arabian Peninsula.
A U.S. Congressional report in 2011 warned that the group was an "emerging threat" to the United States. Boko Haram has denied forging ties with foreign groups.
There is little firm evidence that Boko Haram has ambitions beyond Nigeria, despite claiming the abduction of a French family in northern Cameroon in February last year.
"They do have links and they share information," Tayo says. "But whether Boko Haram is actively part of Al-Qaeda is up for debate, because at the moment the conflict is contained in a certain part of Nigeria."