A car bomb attack outside a church in northern Nigeria on Easter Sunday left at least 20 dead and scores wounded, a rescue source said.
The explosion, a stark reminder of Christmas Day attacks that left dozens dead in the country, occurred in the town of Kaduna, where motorcycle taxi drivers and passersby caught much of the blast.
At least one car said to be driven by a suicide bomber was involved in the attack, though a rescue official speaking on condition of anonymity said two vehicles packed with explosives detonated.
"Now we have 20 dead from the twin explosions," the rescue official, who was not authorised to speak publicly, told AFP. Officials were still counting the number of wounded, he added.
"Bombs concealed in two cars went off just opposite this church," he said.
A police officer at the scene said a man believed to be a suicide bomber driving a car was stopped at a checkpoint near the church and turned back, but drove to a nearby area close to a hotel and detonated the bomb.
Other cars in the area were damaged, but it was unclear if they were also carrying explosives, he said.
A spokesman for the national emergency management agency said most of the victims appeared to be motorcycle taxi drivers who were in the area at the time.
Police confirmed the explosion was a bomb, but did not officially comment further.
"We have a bomb explosion. We are trying to sort things out," police spokesman Aminu Lawal told AFP.
Residents reported seeing dead and injured being taken away. An AFP correspondent said he saw ten bodies, while one resident said he counted at least ten wounded.
Another resident said that "from my balcony, I could see policemen loading the dead and the injured into waiting vans."
One resident said the explosion was strong enough to shake his house and cause his ceiling to cave in. He ran to the site, which had already been cordoned off, but he said he could see damage to the Assemblies of God Church and cars.
Islamist group Boko Haram carried out a series of attacks on churches and other locations on Christmas Day. The worst of those attacks occurred at a church outside the capital Abuja, where 44 people died.
Authorities, as well as foreign embassies, had warned of the possibility of an attack on Easter Sunday.
The Islamist group's increasingly bloody insurgency has left more than 1,000 people dead since mid-2009. Police and soldiers have often been the victims of such attacks, though Christians have occasionally been targeted as well.
The group also claimed responsibility for the August suicide bombing of UN headquarters in the capital Abuja, which killed 25 people.
Its deadliest attack yet occurred in the northern city of Kano on 20 January, when coordinated bombings and shootings left at least 185 people dead.
Nigeria, Africa's most populous nation and largest oil producer, is roughly divided between a mainly Muslim north and predominately Christian south.
Kaduna is a major cultural and economic centre in Nigeria's north.