Kaduna - Two suicide bombs on Sunday killed at least 11 people at a church in a barracks in Kaduna, where the Islamist sect Boko Haram is waging a campaign of violence, the military said.
Army spokesperson Bola Koleoso said a bus drove into the side of the St Andrew Military Protestant Church at the Jaji barracks and exploded about five minutes after a service had started.
At least 30 people were injured.
Explosives inside a car were detonated outside the church ten minutes later, he said.
A military source who witnessed the attack said the second bomb was the most deadly, killing people who went to help the injured from the first blast.
Witnesses said the barracks was cordoned off and ambulances carried the wounded to hospital.
There was no claim of responsibility but Islamist sect Boko Haram has frequently attacked the security forces and Christian churches in its fight to create an Islamic state in Nigeria.
A suicide bomber last month killed eight people and injured more than 100 at a church in another part of Kaduna state.
A bomb attack in a church in Kaduna state in June triggered a week of tit-for-tat violence that killed at least 90 people.
Gunmen killed six people in a village in northern Kaduna state earlier this month.
The area was at the heart of post-election violence in April last year that left hundreds dead and thousands displaced.
Boko Haram's purported spokesperson Abu Qaqa, who used to confirm the sect's attacks in phone calls to journalists, was killed by the military in September, the army said.
Since then there has been little public communication by the group.
Nigeria's army on Saturday offered about $1.8m for information leading to the capture of 19 leading members of Boko Haram.
At least 2 800 people have died in fighting since Boko Haram's insurrection began in 2009, according to Human Rights Watch.