By Garba Mohammed and Isaac Abrak
KADUNA, Nigeria (Reuters) - Two suicide bombs killed at least 11 people on Sunday at a church in a barracks in northern Nigeria, where the Islamist sect Boko Haram is waging a campaign of violence, the military said.
Army spokesman Bola Koleoso said a bus drove into the side of the St. Andrew Military Protestant Church at the Jaji barracks in Kaduna state and exploded at around 1105 GMT, five minutes after a service had started.
Explosives inside a Toyota Camry were detonated outside the church ten minutes later, he said. The military said at least 30 were injured.
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, where the 160 million population is evenly split between Christians and Muslims.
A suicide bomber killed eight people and injured more than 100 last month at a church in another part of Kaduna state, which has a mixed Muslim and Christian population and often suffers from sectarian tensions.
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 spokesman 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 290 million naira ($1.8 million) for information leading to the capture of 19 leading members of Boko Haram, including 50 million naira for the sect's self-proclaimed leader Abubakar Shekau.
At least 2,800 people have died in fighting since Boko Haram's insurrection began in 2009, according to Human Rights Watch. Most in the northeast of the country, where the sect usually attacks politicians and security forces.
Former Prime Minister Tony Blair visited Nigeria with the Archbishop of Canterbury-designate Justin Welby last week to launch a program by Blair's foundation to reconcile religious differences in Africa's most populous nation.
The foundation said it was at consultancy stage and gave no details on how much would be spent or who would benefit.
(Writing by Joe Brock; Editing by Andrew Roche)