'Many dead' after blast at UN office in Nigeria

A car bomb has exploded outside the United Nations' main office in Nigeria's capital, flattening one wing of the building and killing an unknown number of people.

Witnesses said the sedan drove through one of the UN compound's gates and made its way close to the four-story building before the explosion.

"I saw scattered bodies," said Michael Ofilaje, a UNICEF worker at the building. "Many people are dead."

He said it felt like "the blast came from the basement and shook the building".

The building in Abuja houses about 400 employees of the UN in Nigeria, including the majority of its offices.

Alessandra Vellucci, a spokeswoman for the UN office in Geneva, confirmed that the global body's offices in Abuja had been bombed.

She said there was no word yet on casualties.

The building, located in the same neighbourhood as the US embassy and other diplomatic posts in Abuja, had a huge hole punched in it.

Local police spokesman Jimoh Moshood confirmed the blast, but said police were still investigating the cause. Reuben Abati, a spokesman for President Goodluck Jonathan, said the presidency would later issue a statement on the attack.

No one immediately claimed responsibility for the blast, but oil-rich Nigeria faces terrorism threats on multiple fronts.

Last year, a militant group from the country's crude-producing Niger Delta blew up car bombs in the capital during Nigeria's 50th independence anniversary ceremony, killing at least 12.