International pressure is mounting on the Nigerian government over recent mass killings near the city of Jos.
Police say 109 people - thought to be mostly Christians - died in Sunday's bloodshed. Earlier reports put the toll at more than 500.
The violence followed sectarian killings near Jos in January that left more than 300 dead, most of them believed to be Muslims, the BBC reports.
France has urged Nigeria to prosecute those responsible for the massacres, while Britain says it is raising its concerns at a senior level.
The governor of Nigeria's Plateau state has accused military commanders of ignoring warnings of attacks this week.
The Anglcian archbishop of Jos, Benjamin Kwashi, is calling for better intelligence-gathering to prevent such violence.
"It's not a simple criminal activity," he told the BBC, "it's calculated, deliberate."
Police have arrested 200 people and say they will charge 49 people with murder.