A suicide bomber blew his car up outside a church and gunmen opened fire on another service in Nigeria on Sunday, killing three people and wounding dozens in attacks claimed by Boko Haram.

The assaults were the latest in a series targeting churches in Africa's most populous nation and largest oil producer, with many of the previous attacks also claimed by the Islamist group, whose insurgency has killed more than 1,000 people since mid-2009.

A purported spokesman for Boko Haram claimed responsibility for Sunday's attacks and threatened further violence.

"We are responsible for the suicide attack on a church in Jos and also another attack on another church in Biu," the spokesman calling himself Abul Qaqa told reporters in the northeastern city of Maiduguri in a phone conference.

"We launched these attacks to prove the Nigerian security wrong and to debunk their claim that we have been weakened by the military crackdown," he said, speaking in the Hausa language common throughout Nigeria's north.

"The Nigerian state and Christians are our enemies and we will be launching attacks on the Nigerian state and its security apparatus as well as churches until we achieve our goal of establishing an Islamic state in place of the secular state."

The attacks took place at evangelical churches in the central city of Jos and the northeastern town of Biu, both of which have been hit before by violence blamed on Boko Haram.

"The suicide bomber did not drive into the church before the explosion. He was in front of it," police spokesman Abuh Emmanuel said of the Jos attack. "The church building collapsed entirely due to the intensity of the bombing."

Local government spokesman Pam Ayuba told AFP that two people plus the bomber died and 41 were wounded.

AFP