Six people have been killed in bomb blasts at a Nigerian newspaper's offices in the capital Abuja and in the northen city of Kaduna.
Three people were killed at the blast in Abuja, according to the Reuters news agency, while the second explosion at the ThisDay newspaper's offices in the city of Kaduna killed another three people.
The explosion in Abuja occurred about 11:30am local time on Thursday. Gbayode Somuyiwa, ThisDay's spokesman, did not immediately return calls for comment.
"Three people died, including the attacker," said a rescue official, who spoke on condition of anonymity.
A local emergency management spokesman in Kaduna confirmed that at least three people were killed there.
Nwakpa Nwakpa, a spokesman for the Nigeria Red Cross, said the "suicide bomber" rammed through the front gates of
the ThisDay office in Abuja and drove a car loaded with explosions into the newspaper's reception.
Nwakpa said others were wounded in the attack.
Police and paramilitary forces were on the scene and had surrounded the offices where the blast had taken place. An Associated Press news agency reporter who heard the explosion said it was very large.
A police spokesman told the AFP news agency earlier on Thursday, "We heard something like that happened, but we don't have the details yet."
A National Emergency Management Agency confirmed the explosion, saying it occured in the Jabi district of Abuja.
"NEMA officials are on the ground," said Yushau Shuaib. "They are trying to move those injured to the hospitals, but we don't have any information on casualties yet."
It was earlier reported that attackers had carried out assaults on two police stations and a bank in a northern Nigerian town.
The attackers allegedly raided the northeastern town of Bajoga in Gombe state, using guns and bombs, beginning late on Wednesday and into Thursday morning.
Residents reported a badly damaged regional police station, but details were sketchy. Residents and authorities were unclear about the number of casualties at the time.
"There were bombings and gun attacks on the area command and divisional police station in Bajoga town by some gunmen," said Ahmed Mohammed, a police spokesman.
"They attacked these police facilities with IEDs and assault rifles. There was a shootout between the attackers and the policemen at the facilities."
One resident said the sounds of explosives and rifles were heard during the attack, which lasted until 1:00am.
"People in the area around the police buildings fled to other parts of the town," he said. "The area has been cordoned off by security personnel."
Victims at the bank attack seemed to have been robbed as well, AFP news agency reported.
The police spokesman said it was not yet clear whether the attackers were members of the armed group Boko Haram or if they were armed robbers.
Boko Haram has carried out scores of attacks in Nigeria's north as part of an insurgency that has left more than 1,000 people dead since mid-2009, but gangs have also committed crimes under the guise of the radical group, which seeks the imposition of an interpretation of Islamic law in Nigeria.