Nigeria's military, which has frequently been accused of human rights abuses in its decade-long fight against Boko Haram and more recently Islamic State's West African branch, did not immediately respond to requests for comment.
Previous allegations have sparked investigations by the International Criminal Court in the Hague and hampered Nigeria's ability to purchase arms, a source of frustration for its military's leaders. However, convictions of soldiers have been rare and the military has repeatedly denied wrongdoing.