A suicide bombing outside Nigeria's national police headquarters in Abuja has killed at least two people, including the bomber.
The blast is believed to be the first suicide bombing in Nigeria.
A spokesman for the Islamist radical group Boko Haram claimed responsibility for the blast in an interview with VOA.
The group is blamed for a string of deadly attacks in Nigeria's north that have targeted police officers, government officials and other authority figures.
Police say the vehicle carrying Thursday's suspected bomber was stopped outside of police headquarters and was directed to the parking lot to be searched when the blast went off. They say a traffic warden who entered the car to show the driver where to park was also killed in the explosion.
The Nigerian Red Cross says at least seven people were wounded in the blast, and police say more than 30 cars were destroyed.
Separately, a bomb went off in Nigeria's northeastern Borno state Thursday, killing four children. Police say the children were playing nearby when the bomb went off inside a home in the town of Damboa.
There was no immediate claim of responsibility.
Nigeria experiences frequent bomb attacks, stemming from political and sectarian tensions.
Last October, 12 people died in twin car bombings in Abuja on Nigeria's independence day. Authorities blamed that attack on militants from the country's volatile Niger Delta region.
Boko Haram is believed to have carried out many bombings and shootings in Borno state. The group is pushing to impose strict Islamic law across the north.
Boko Haram launched a brief uprising against the government in July 2009, sparking a heavy military response and a week of fighting that killed some 700 people.