Over 80 feared dead in church attack, sources say

More than 80 people are feared to have died in Sunday's attack on a church in southwestern Nigeria, sources told ABC News on Wednesday.

A source with direct knowledge of the investigation said the bodies of 82 victims were in a local morgue. Another source briefed on the latest U.S. intelligence assessment said the estimate was over 80. Both sources spoke on the condition of anonymity because they didn't have authorization to speak to the press about the ongoing probe. A spokesperson for the Nigeria Police Force, which is leading the investigation, told ABC News on Wednesday that the probe is ongoing and they can not confirm the death toll at this time.

Richard Olatunde, a spokesperson for the Ondo state governor, told ABC News on Wednesday that the casualty count was 40 people dead and 86 wounded, including 61 who were still hospitalized. However, those numbers are likely an underestimate.

The bloodshed occurred at St. Francis Catholic Church in the town of Owo in Ondo state, more than 200 miles northwest of Lagos, Nigeria's largest city, and over 200 miles southwest of Abuja, the Nigerian capital. The church was holding a service for Pentecost Sunday, a Christian holiday celebrated on the 50th day after Easter, when suddenly explosives detonated and gunshots rang out at around 11:30 a.m. local time, according to police

Several gunmen who were disguised as congregants were inside the church and opened fire at worshippers, police said, while other armed men who had positioned themselves around the church fired into the building from different directions and at worshippers as they tried to escape.

The assailants fled the scene in a stolen Nissan and remain at large, according to police, who said the vehicle has since been recovered.

Police said they have also recovered three undetonated improvised explosive devices (IEDs) from the scene, along with fragments of detonated IEDs and pellets of expended AK-47 ammunition.

The exact number of perpetrators was unknown and police have yet to identify them. A motive for the massacre was also not immediately clear, as no group has claimed responsibility.

The Catholic Laity Council of Nigeria said in a statement on Monday that the gunmen were "suspected to be bandits."

Meanwhile, health workers at the Federal Medical Center in Owo, which was treating victims of the attack, told ABC News on Monday that there was an urgent need for blood donations for the wounded.

Nigerian Inspector-General of Police Usman Alkali Baba has ordered a "full-scale" and "comprehensive" investigation into the incident and has deployed specialized police units to help track down the assailants, according to police.

Sunday's attack was largely unprecedented in Ondo, which has been considered one of Nigeria's most peaceful states. Violent attacks and kidnappings for ransom have become rife in other parts of the West African country.