Graphic new video footage from northeastern Nigeria shows the country's military carrying out abuses against civilians as part of its fight against Boko Haram, Amnesty International said Tuesday. The human rights group also accused the military of killing of more than 600 released prisoners.
The violence against civilians constitutes war crimes, Amnesty alleged.
One video shows military personnel and civilian vigilantes calling five detainees from a row of 16 young men and boys, then slitting their throats one by one before dumping the bodies into an open grave.
The rights group described the civilian vigilantes as "state-sponsored militias."
The Amnesty allegations back up previous reports by The Associated Press that human rights abuses are being committed by all sides in Nigeria. Nigerian authorities have rejected previous accusations, insisting the military follows international best practices in its fight against Boko Haram.
The Nigerian military is studying the video "with a view to identifying those behind such acts," said Defense Headquarters spokesman Chris Olukolade in an email. He added there will be "legal action against any personnel or anyone found culpable."
Amnesty said it obtained the footage from "numerous sources" in Borno state, the militant group's birthplace and stronghold. The video reveals "graphic evidence of multiple war crimes being carried out in Nigeria," according to the group, which said it independently confirmed from several military sources that the armed captors in the footage "were indeed military personnel."
More than 4,000 people, mostly civilians, have been killed this year alone "by all sides" in the conflict, said Amnesty, compared with an estimated 3,600 people killed in the first four years of the insurgency.
Boko Haram wants to create an Islamic state in Nigeria, whose population of more than 170 million people is almost evenly divided between a mainly Muslim north and largely Christian south.
The video footage is "proof of the appalling crimes being committed with abandon by all sides in the conflict," said Salil Shetty, Amnesty International's secretary-general.
Some of the footage was apparently taken on March 14, the same day that Boko Haram broke into a military detention center in Giwa barracks, freeing hundreds of prisoners. Amnesty says the military recaptured more than 600 of those prisoners and killed them.
Nigeria's fight against the group began in 2009 and took the international spotlight in mid-April when the militants kidnapped more than 200 schoolgirls, who remain captive.
The Associated Press