Over 7,000 males have died while in custody of the Nigerian military over the last four years, Amnesty International has revealed in a new report.
Over 20,000 people are said to have been arrested in operations against Boko Haram militants, the UK-based rights group said.
Nigeria's military has rejected the allegations, calling the report biased and the statistics "spurious".
The report, entitled Stars on their shoulders, Blood on their hands, names several senior officers and calls for investigations into their role in murder, torture and enforced disappearances.
“This sickening evidence exposes how thousands of young men and boys have been arbitrarily arrested and deliberately killed or left to die in detention in the most horrific conditions. It provides strong grounds for investigations into the possible criminal responsibility of members of the military, including those at the highest levels,” said Salil Shetty, Amnesty International’s Secretary General.
“Whilst an urgent and impartial investigation of these war crimes is vital, this report is not just about the criminal responsibility of individuals. It is also about the responsibility of Nigeria’s leadership to act decisively to end the pervasive culture of impunity within the armed forces.”
Army spokesperson Maj Gen Chris Olukolade said the report "went out to gather names of specified senior officers, in a calculated attempt to rubbish their reputation".
See the full report here.