The National Emergency Management Agency’s central region chief, Ishaya Chonoko, said several people were also injured in the raid and that rescue workers were at the site.
Monday night unknown gunmen invaded the Deeper Life Church at Otite area in Okene, killed 16 worshippers and wounded many others.
The Commander of the Joint Military Task Force in Lokoja, Lt-Col. Gabriel Olorunyomi, confirmed the incident.
“They were doing their normal Monday evening service. When we went there we discovered the church had been attacked. Instantly we saw 15 people dead, including the pastor,” he explained.
The military has since learned that an additional four people had died from their injuries, Olorunyomi explained.
He said 15 worshippers died instantly in the attack while another died on the way to the hospital.
The commander said that many injured persons were rushed to hospitals in Lokoja, a distance of 40 minutes driving on the road from Okene.
He said the casualty figure might rise considering that some sustained heavy injuries.
No group has claimed responsibility for the attack as yet
There was no immediate claim of responsibility and Kogi state police spokesman Simon Ile told AFP there were no early indications as to the culprits.
“They entered the church…they just opened fire and they went away. We don’t know their motives yet,” he said.
While Muslims have often been its victims, Boko Haram, which has said it wants to create an Islamic state in northern Nigeria, has increasingly attacked Christians, often during church services.
In addition to churches, Boko Haram has also targeted Muslim figures as well as a range of others, including the United Nations building in the capital Abuja.
President Goodluck Jonathan said in June that Boko Haram was seeking to incite a religious crisis by attacking churches in an attempt to destabilise the government.
Jonathan described how the group had moved from targeting local rivals to government institutions and now churches.
Nigeria, Africa’s most populous nation and largest oil producer, is roughly divided between a mainly Muslim north and predominately Christian south.
In a video posted to YouTube on Saturday, the suspected leader of Boko Haram criticised Jonathan as well as US President Barack Obama over Washington’s decision to label him a “global terrorist”.
It was unclear when the video was made, but it marked the first time Abubakar Shekau publicly addressed the terrorist designation slapped on him by the United States in June.
In addition to Shekau, the US State Department also announced the designations for Abubakar Adam Kambar and Khalid al-Barnawi. Kambar and Barnawi were said to be linked to Boko Haram and Al-Qaeda in the Islamic Maghreb (AQIM), Al-Qaeda’s north African branch.
Some US lawmakers and the leader of Nigeria’s main Christian body have been pushing Obama’s administration to label Boko Haram as a whole a terrorist organisation.
American diplomats have stressed that the group remains domestically focused, with deep poverty in Nigeria’s north a main factor in its emergence. They have argued that labeling it a terrorist organisation would simply boost its profile and possibly complicate efforts to resolve the crisis.
Addressing US lawmakers last month, Ayo Oritsejafor, president of the Christian Association of Nigeria, claimed that Boko Haram sought the “removal of the Christian presence in Nigeria.”