Targeted killings of ethnic individuals
Secret killings have been on the rise since this year's second massacre, in early March, say Christian and Muslim community leaders, government officials, and police.
"We have started receiving reports of corpses being found here and there. It started happening after the March 7 incident," says Femi Oyeleye, the head of the state's criminal investigation department, referring to coordinated mob attacks by Muslims on members of the mainly Christian Berom ethnic group.
Those March killings are said to have been reprisals for religious clashes that killed scores in January.
According to Mr. Oyeleye, 25 corpses unrelated to any major attacks were found in Jos during March and April – far above the average rate of three corpses a month during the 12 months leading up to February.
Lawal Ishaq, a local lawyer who documents secret killings against Muslims, recorded 36 deaths in March and April.
Death tolls are sensitive in Jos – and highly unreliable.
The figures for the March massacre, in which mostly Christians were killed, range from 150 to 450.
Similar uncertainty shrouds the January massacre, in which mostly Muslims died.
"Each side inflates the figures, and then the high numbers are used to justify revenge attacks," says Henry Mang, a researcher at Jos University's Centre for Conflict Management and Peace Studies.
Ethnicity and politics also play a role
In Jos, religion is just one cause of conflict.
The fighting falls broadly along ethnic lines, with the mostly Christian Berom group against the largely Muslim Hausa and Fulani groups.
The Hausa and Fulani are officially deemed settlers in Plateau State, even though some have lived here for generations, and say that as a result they are excluded from political office.
The state government counters that the so-called settlers have been given a small number of roles and are now trying to take over.