U.N. Secretary General Ban Ki-moon said the final casualty toll was likely to be considerable and Nigerian President Goodluck Jonathan ordered tighter security around the capital after what he called a “most despicable assault”.
Security sources and witnesses said the car rammed into the building and blew up, badly damaging parts of an office complex where close to 400 people normally work for U.N. agencies.
“We do not yet have precise casualty figures but they are likely to be considerable,” Ban said.
“This was an assault on those who devote their lives to helping others,” he said in a statement. “We condemn this terrible act, utterly.”
Body parts were strewn on the ground as emergency workers, soldiers and police swarmed around the building, cordoned roads and rushed the wounded to hospital.
“Different people have been taken to different hospitals so we’re not sure of casualty figures. It is at least 18,” said Mike Zuokumor, Abuja police commissioner.
The BBC reported that a spokesman for the Islamist group Boko Haram had said in a phone call that it had carried out the attack. The BBC gave no further details.