The U.S. envoy to the United Nations was in Central African Republic Thursday to urge political and religious leaders to end brutal violence, warning the people were "in profound danger".

Samantha Power is the highest-level U.S. official to visit the CAR, which has plunged into anarchy with sectarian violence that has killed hundreds of people.

A Nigerian failed asylum seeker who has been on hunger strike for around 100 days was removed from Britain on Wednesday following an unsuccessful legal battle.

Isa Muazu has been returned to Nigeria, immigration minister Mark Harper said.

Nigeria's President Goodluck Jonathan lost his majority in parliament on Wednesday after 37 lawmakers bolted his party for a new opposition coalition, the latest political blow to hit the embattled leader.

In a letter presented to the speaker of the lower house, the lawmakers elected under Jonathan's Peoples Democratic Party (PDP) declared that they had joined the All Progressives Congress, stripping the PDP of its majority in 360-seat chamber.

Attacks by Islamist group Boko Haram in Nigeria's restive northeast have killed more than 1,200 people since May, when a state of emergency was declared in the region, the United Nations said Monday.

Nigeria placed the states of Adamawa, Borno and Yobe under emergency rule on May 14, following waves of deadly violence by the Islamist rebels.

January 1, 2014 marks the centenary of the amalgamation of southern and northern Nigeria but the anniversary looks set to be muted, amid lingering questions about whether the union can hold.

In the run-up to the landmark, opinion is split between those who think amalgamation has been a boon and others who consider it the first step in the creation of a still-failing state.

Boko Haram's leader said in a video obtained by Agence France Presse on Thursday that the group was behind a daring raid on military installations in the north Nigerian city of Maiduguri earlier this month.

"Allah the Almighty has given us victory in the attack we launched inside Maiduguri (which was) called Borno in ancient times," said Abubakar Shekau in a 40-minute clip.

A Nigerian asylum seeker believed to be near death after a three-month hunger strike has been granted more time to fight his deportation from Britain, his lawyers said Thursday.

Isa Muazu, who has been on hunger strike since September, was sent to Nigeria last week but the plane turned back, reportedly because Nigerian authorities refused to let it land.

The airport in Nigeria's capital Abuja was temporarily closed Thursday, stranding thousands of passengers, after a Saudi cargo plane overshot a runway on landing and blocked part of the tarmac, officials said.

"No casualty was recorded," said aviation ministry spokesman Joe Obi. "Efforts are underway to move the aircraft away."

Nigeria said on Wednesday that 500 people who were arrested during security operations against Boko Haram militants in three northeast states should be put on trial for terror offences.

The 500 are among nearly 1,400 detained in Borno, Adamawa and Yobe states between July and September, the country's defense spokesman, Chris Olukolade, said in a statement.

Nigeria's military on Tuesday restored the mobile phone service in the embattled city of Maiduguri, a day after a major raid by Islamists which prompted a round-the-clock ban on movements.

The phones were switched off in May when a state of emergency was declared in the area, a move the military said would help block Boko Haram from coordinating attacks in the northeastern city.