There was no immediate claim of responsibility but police said they suspected radical sect Boko Haram, which has been behind almost daily attacks in the remote northeast and claimed a series of bomb blasts further afield last month.
Dozens of vehicles were set ablaze by the blast, which struck the car park outside the building. Thick black smoke billowed into the sky. Red Cross workers loaded body bags into ambulances but it said it was too early to give a death toll.
Police spokesman Olusola Amore said the vehicle carrying the suspected bomber was stopped outside the building and directed to the car park to be searched.
“The traffic warden who entered the vehicle of the suicide bomber to direct him to the car park was blown up along with him,” Amore said.
Witnesses said police failed in an attempt to stop a vehicle entering the car park shortly before the explosion was heard. The National Emergency Management Agency (NEMA) also said that the explosion was the work of a suspected suicide bomber. Security analysts said it was difficult to say whether the bomber had meant to blow himself up or whether the explosives had detonated accidentally while he was still in the vehicle.
If proved to have been deliberate, it would be the first suicide bomb attack in Africa’s most populous nation.
The blast at what should be one of Nigeria’s most secure buildings raised questions about national security less than three weeks after President Goodluck Jonathan was sworn in for his first full term in office.
Co-ordinated bomb blasts at popular drinking spots in the towns of Bauchi, Zaria and Zuba killed at least 16 people hours after Jonathan was inaugurated on May 29. Those explosions were claimed by Boko Haram.
Jonathan has named some members of his new administration, including retaining his former national security adviser, but the country is still without a Cabinet.
Boko Haram has carried out almost daily attacks in and around the northeastern city of Maiduguri in recent months.
Its targets have been soldiers, policemen, prison warders and politicians as well as religious and traditional rulers opposed to its ideology. The sect has warned it would carry out more strikes if its demands were not met.
Security analysts feared it might try to strike in Abuja.
Jonathan has voiced support for dialogue with Boko Haram but some analysts have privately questioned whether the security agencies have taken the group seriously enough.
Police Inspector-General Hafiz Ringim, who witnesses said entered the building shortly before the blast, was quoted this week as saying the group’s days were “numbered.”
A letter, claiming to be from Boko Haram, was delivered to a newspaper in Maiduguri the next day warning civilians to “restrict their movements” throughout northern states and in Abuja as more attacks were planned.
“Suicide bombers, if confirmed, are a significant escalation. I guess this was payback for Ringim’s imprudent boast,” said one Western diplomat.
Jonathan won elections in April which, while deemed Nigeria’s most credible for decades, were marred by violence and triggered resentment in some parts of the mostly Muslim north.
Rights groups say as many as 800 people were killed in rioting in north after Jonathan, a Christian from the southern oil-producing Niger Delta, was announced the winner.
The government dealt with a previous uprising by Boko Haram in Maiduguri in 2009 by sending in the military, leading to days of gun battles in which hundreds of people were killed.
Jonathan could stoke further resentment if he were to do the same again, particularly as critics may draw comparisons with militants in his Niger Delta home region who were given amnesty by the government also in 2009.
“This attack further highlights the need for an able and effective government team to be formed quickly,” said Kayode Akindele, partner at Lagos-based advisory firm JMH-TIA Capital.
“Nigerians are seeking answers from their new president.”
