"A car drove into the church premises ... then detonated the bomb," an anonymous military officer told Reuters.
Nigeria's National Emergency Agency confirmed to Reuters there was an explosion, "likely at a worship center."
A military spokesman told the BBC the bombing was "surprising and an embarrassment."
The first car bomb did not kill anyone. However, the military spokesman said, "curious worshippers gathered around the scene looking at the debris... and that was when the second blast happened."
No group has claimed responsibility, but many suspect the Salafist Jihadist terrorist group Boko Haram. The group has a reputation of bombing churches in Nigeria, often in the northern Kaduna state where sectarian violence between Christians and Muslims is common.
On Nov. 22, a suicide bomber attacked a church in northern Nigeria, killing at least two people and wounding dozens, according to CNN.
In October, Boko Haram (the name roughly means western education is a sin), a suicide bomber dove an SUV packed with explosives into a church. Seven died and hundreds were injured.
In June, a Boko Haram church bombing began sectarian violence that ended with about 90 people dead.