A car bomb has exploded in a city in central Nigeria, killing an unknown number of people, officials said.
It was not immediately clear how many people died in the blast in Kaduna, the capital of Kaduna state, though emergency officials found corpses around the wreckage of the car, local police spokesman Aminu Lawan said.
The blast struck on a major roadway in the city near local eateries, a hotel and at least one church, witnesses said.
"It exploded and affected the people around there," Lawan said.
Security forces surrounded the site of the blast as residents fled in fear.
Yushau Shuaib, a spokesman for Nigeria's National Emergency Management Agency, said it appeared many of the victims were motorcycle taximen who typically gathered there.
No one immediately claimed responsibility for the attack.
The blast happened as the UK and the US had warned its citizens living in the oil-rich nation that violence was likely over the Easter holiday. Nigeria's weak central government is under increasing attack from a radical Islamist sect known as Boko Haram.
Boko Haram, whose name means "Western education is sacrilege" in the Hausa language of Nigeria's north, is waging an increasingly bloody fight with security agencies and the public.
The sect, employing suicide bombers and assault-rifle shootouts, has attacked both Christians and Muslims, as well as the United Nations' headquarters in Nigeria.