At least 38 people have died in a car bombing in the northern Nigerian city of Kaduna, officials said.
Many others were injured in the attack, which took place when officials stopped the vehicle as it approached a church.
Just hours afterwards, a bomb exploded in the central city of Jos, injuring several people.
No-one has admitted carrying out the bombings, but suspicion has fallen on Boko Haram, a militant group which had warned of attacks over Easter.
Kaduna lies on the dividing line between Nigeria's largely Christian south and Muslim north.
The area has been the scene of a religious conflict in recent years that has claimed hundreds of lives.
The blast in Kaduna took place on a busy road in a central area near restaurants and a hotel.
Witnesses say debris was thrown dozens of metres from the centre of the blast. Many of the dead are thought to be motorcycle taxi drivers and beggars.
Kaduna police commissioner, Mohammad Jinjiri Abubakar, said police had been pursuing a vehicle when it collided with another car and caused an explosion.
According to residents, the car had been travelling towards a church when it was turned away at a roadblock, and then followed by police.
"A suicide bomber in a vehicle was moving towards the ECWA Church and the All Nations Christian Assembly," said Tony Udo, a Kaduna resident, told Reuters news agency.
"Security agents accosted and repelled him. While he was driving away, the bomb went off at Junction Road, near the Stadium roundabout, killing the bomber and some commercial motorcyclists," he added.
"We were in the holy communion service and I was exhorting my people and all of a sudden, we heard a loud noise that shattered all our windows and doors, destroyed our fans and some of our equipment in the church," Pastor Joshua Raji said.
Meanwhile, security forces helped evacuate those injured after an explosion in the Tudan Wada area of Jos, a spokesman for the national emergency management agency (NEMA) said.