Gunmen have attacked a church in north-east Nigeria, killing at least six people, the church's pastor says.
Johnson Jauro said the killings took place when gunmen burst into his Deeper Life Church in Gombe, capital of Gombe state.
He said his wife was among those killed. Ten other people were injured.
Nigeria has recently experienced a surge in ethnic and sectarian violence. The government declared a state of emergency in parts of the country.
"The attackers started shooting sporadically. They shot through the window of the church, and many people were killed including my wife," Mr Jauro told Reuters news agency.
"Many members who attended the church service were also injured."
No group has said it carried out the attack, but the Islamist sect Boko Haram recently carried out a string of bombings on Christmas Day, including against a church in the capital, Abuja, which killed dozens of people.
There have been unconfirmed reports that Boko Haram has told all southerners - who are mostly Christians and animists - to leave the largely Muslim north.
Earlier on Thursday, two suspected members of Boko Haram were arrested after a father and son were killed in Maiduguri in neighbouring Borno state.
Attacks by Boko Haram have become increasingly frequent and are a major problem for the Nigerian authorities.
President Goodluck Jonathan has vowed to "crush" the group.
Several northern states surrounding Gombe have had their borders sealed off under the state of emergency declared by Mr Jonathan following the Christmas bombings.
Boko Haram is fighting to create an Islamic state and wants to impose Sharia law across Nigeria.
Followers of Boko Haram believe any political or social activity associated with Western values should be banned.
This includes voting in elections, wearing shirts and trousers and receiving a secular education.
Boko Haram regards the Nigerian state as being run by non-believers and this was the case even when the country had a Muslim president.
In unrelated violence on Sunday, at least 50 people died in the eastern state of Ebony in clashes between two ethnic groups over a land dispute.
To win at the first round, a candidate not only needs the majority of votes cast, but at least 25% of the vote in two-thirds of Nigeria's 36 states. Goodluck Jonathan, of the PDP, reached that threshold in 31 states; runner-up Muhammadu Buhari of the CPC only did so in 16 states.
Nigeria's 160 million people are divided between numerous ethno-linguistic groups and also along religious lines. Broadly, the Hausa-Fulani people based in the north are mostly Muslims. The Yorubas of the south-west are divided between Muslims and Christians, while the Igbos of the south-east and neighbouring groups are mostly Christian or animist. The Middle Belt is home to hundreds of groups with different beliefs, and around Jos there are frequent clashes between Hausa-speaking Muslims and Christian members of the Berom community.
Despite its vast resources, Nigeria ranks among the most unequal countries in the world, according to the UN. The poverty in the north is in stark contrast to the more developed southern states. While in the oil-rich south-east, the residents of Delta and Akwa Ibom complain that all the wealth they generate flows up the pipeline to Abuja and Lagos.
Southern residents tend to have better access to healthcare, as reflected by the greater uptake of vaccines for polio, tuberculosis, tetanus and diphtheria. Some northern groups have in the past boycotted immunisation programmes, saying they are a Western plot to make Muslim women infertile. This led to a recurrence of polio, but the vaccinations have now resumed.
Female literacy is seen as the key to raising living standards for the next generation. For example, a newborn child is far likelier to survive if its mother is well-educated. In Nigeria we see a stark contrast between the mainly Muslim north and the Christian and animist south. In some northern states less than 5% of women can read and write, whereas in some Igbo areas more than 90% are literate.
Nigeria is Africa's biggest oil producer and among the biggest in the world but most of its people subsist on less than $2 a day. The oil is produced in the south-east and some militant groups there want to keep a greater share of the wealth which comes from under their feet. Attacks by militants on oil installations led to a sharp fall in Nigeria's output during the last decade. But in 2010, a government amnesty led thousands of fighters to lay down their weapons.