They said the car rammed into the office building before exploding in an attack similar a June assault on the Abuja police headquarters claimed by Boko Haram, a Nigerian radical Islamist sect.
“We have had 10 dead and there could be more,” said a medical official who declined to give his name.
The U.N. building was blackened from top to bottom and the remains of a car had fallen into the basement. Soldiers, firefighters and rescue workers swarmed over the area.
An Abuja-based security source said he suspected the attack was carried out by a Nigerian Islamist group, whose strikes have been growing in intensity and spreading further afield, or the North African arm of al Qaeda.
“This is very likely the work of Boko Haram and, or, AQIM (al Qaeda in the Islamic Maghreb) and is a serious escalation in the security situation in Nigeria,” the security source said. “This is the worst thing that could have happened.”