At least two people have been killed in a suicide bomb attack on the police headquarters in the Nigerian capital, Abuja.
Officials say the suspected bomber was killed in the building's car park, and many vehicles were destroyed.
Police spokesman Olusola Amore said Islamist group Boko Haram was suspected of being behind the attack.
The Red Cross says another four bodies have been found at the site of the blast.
The BBC says the attack is an embarrassing strike at the very heart of the Nigerian security establishment.
In the last few weeks, Boko Haram, which usually operates in the north-eastern city of Maiduguri, has been stepping up its attacks on security targets and has claimed it was behind a series of bombings in the capital last month.
Nigeria's police chief had earlier promised sending more troops and equipment to the north to deal with the rebels.