Nigerian government officials claimed on Friday to have struck a two-part deal with Boko Haram, including a ceasefire and the release of 219 schoolgirls, whose abduction last April sparked international outrage.

"Boko Haram issued the ceasefire as a result of the discussions we have been having with them," said Hassan Tukur, who represented the Nigerian government at talks with the militant organization in neighboring Chad. "They have agreed to release the Chibok girls."

The girls have been missing for the past six months, despite international efforts mobilized by the Twitter hashtag campaign #BringBackOurGirls to rescue them from captivity. France, Great Britain and the United States have helped with the search for the girls, while China, Israel and other nations have also provided various forms of assistance.

Nearly 300 girls were kidnapped from a boarding school in the northeastern town of Chibok on April 14, but dozens managed to subsequently escape. Nigerian President Goodluck Jonathan has been criticized by the girls' families for responding slowly to their abduction.

Brutal war in Nigeria's north

Boko Haram, whose name roughly translates to "Western education is sacrilege," seeks to impose a strict interpretation of Shariah law in northern Nigeria. During its early years, the Sunni militant group engaged in isolated skirmishes with Nigerian security forces. But after a bloody government crackdown in 2009, Boko Haram launched a broad insurgency. Last summer, Boko Haram leader Abubakar Shekau declared a caliphate in the areas under the control of his forces.

Boko Haram's insurgency has been characterized by a brutal campaign of bombings and shootings targeting Christian churches, Muslim mosques, schools, markets, bars, villages, police stations and even a UN building. An estimated 5,000 Nigerians have been killed and a further 300,000 displaced by the violence.

In 2013, the Nigerian government declared a state of emergency in the northeastern states of Borno, Yobe and Adamawa. Amnesty International has accused the Nigerian military of war crimes, including extrajudicial killings, in its fight against Boko Haram. The United Nations and Human Rights Watch have also alleged that Nigeria's security forces have committed human rights abuses.

Nigeria's population of 177 million people is 50 percent Muslim and 40 percent Christian. Muslims are concentrated in the north and Christians in the south. The remaining 10 percent of the population practices indigenous beliefs.

slk/shs (AP, AFP, Reuters)