The Nigerian army said two blasts that hit a church in a military barracks in restive Kaduna on Sunday were suicide attacks.
The twin explosions that rocked the St. Andrew Military Protestant Church has lead to the death of 11 people and injuring 30 others, the army confirmed.
"There were twin suicide bombings today at St Andrew Military Protestant Church (in the town of Jaji)," army spokesman Brigadier General Bola Koleosho told AFP, saying the attacks were just 10 minutes apart.
One of the explosions ripped through the church in the barracks in restive Kaduna on Sunday, the army said, with reports that a number of people had been wounded and eleven worshipers killed.
"There were blasts today in a church inside the military barracks in Jaji (in Kaduna state). It happened after the church service," a military spokesman in Kaduna, Colonel Sani Usman, told AFP.
A military officer who did not want to be named said the Protestant church was hit by two explosions.
"The first blast caused no casualties and curious worshippers gathered around the scene looking at the debris... and that was when the second blast happened," he said.
"Many people were injured but I have not received reports of any deaths at the moment."
Jaji lies some 30 kilometres (20 miles) from the state capital Kaduna city which has been hit in the past by deadly attacks blamed on the Islamist sect Boko Haram.
The group has often targeted churches in its bloody insurgency, as well as police and other symbols of the establishment in Nigeria, Africa's most populous country which is divided between a mainly Muslim north and a predominantly Christian south.
The state-run National Emergency Management Agency (NEMA) said "rescuers have been alerted to an explosion at a military formation in Kaduna state today and likely at a worship centre"
Although no group has claimed responsibility for Sunday's church blast, the incident was similar to previous attacks blamed on the Islamist extremist group.
Last month, at least 10 people were killed and 145 wounded in a suicide church bombing and reprisal violence in Kaduna.
Suicide bombings at three churches in June that were claimed by Boko Haram sparked reprisal violence by Christian mobs who killed dozens of their Muslim neighbours, burning some of their victims' bodies.
Muslim groups also formed mobs and killed several Christians.
Apart from churches, security forces, government officials, and other symbols of authority have been targeted by Boko Haram fighters.
The group's insurgency in northern and central Nigeria is believed to have left some 3,000 people dead since 2009, including killings by the security forces.
Boko Haram has claimed to be seeking an Islamic state in Nigeria, Africa's largest oil producer.
However, its demands have repeatedly shifted and it is believed to include various factions with differing aims, in addition to imitators and criminal gangs that carry out violence while posing as members of the group.