Amnesty International has accused the Nigerian military and militia groups of committing “extensive human rights violations” in the country’s battle against the members of the Boko Haram terrorist group.

According to the international rights watchdog, Nigeria’s military and civilian militias fighting the Takfiri group have carried out rights violations in the country’s northeast.

Amnesty International said that it gained access to gruesome video footage, images, and witness testimonies during a recent research mission in Borno State. The watchdog added that it found “fresh evidence of extrajudicial executions and serious human rights violations.”

The images and videos reportedly show “men who appear to be members of the Nigerian military and the Civilian Joint Task Force (CJTF), state-sponsored militias” slitting the throats of detainees and dumping their bodies in mass graves.

“The ghastly images are backed up by the numerous testimonies we have gathered which suggest that extrajudicial executions are, in fact, regularly carried out by the Nigerian military and CJTF,” Amnesty International’s Secretary General Salil Shetty said.

The rights body also said that more than 4,000 people had lost their lives this year alone in the conflict between Nigerian forces and the Boko Haram, “including more than 600 extra-judicially executed.”

Boko Haram is still holding 219 of the 276 schoolgirls it kidnapped from their school in Borno State’s Chibok town, back in April.

The notorious group has repeatedly targeted civilians, mostly in Borno.

Boko Haram - whose name means “Western education is forbidden” - says its goal is to overthrow the Nigerian government.