Violence has flared in the southeastern states this year, killing at least 127 police or members of the security services, according to the police. About 20 police stations and election commission offices have been attacked, local media have reported.
Amnesty said that in response, security forces, including the military, police and the Department of State Services (DSS) intelligence agency have killed dozens of gunmen, as well as civilians, where attacks have taken place.
“The evidence gathered by Amnesty International paints a damning picture of ruthless excessive force by Nigerian security forces in Imo, Anambra and Abia states,” Osai Ojigho, the group’s Nigeria director, was quoted as saying by AFP news agency.
The global rights watchdog said in a Twitter post it had “documented at least 115 persons killed by security forces between January and June 2021”.
“What is needed is an impartial and open inquiry to determine what happened and bring to justice all those suspected of criminal responsibility in fair trials before ordinary civilian courts and without recourse to death penalty,” Amnesty said.
There was no immediate comment by Nigerian authorities.
“I have not seen the statement. So I cannot respond,” national police spokesman Frank Mba told AFP.
Amnesty said relatives of the victims told the rights group that they were not part of the armed groups who were attacking security agents.
“Many of the victims were deposited at government hospitals in Imo and Abia state,” it said.
Amnesty said it also documented cases of arbitrary arrest, ill-treatment and torture in the restive region.
It said that in May 2021, the Imo state government announced the arrest of at least 400 people allegedly linked to the violence.
“Amnesty International’s investigation indicates that most of them were randomly picked up in their homes and off the street and had nothing to do with ESN.”
Local and international rights groups have repeatedly accused Nigerian security forces of rights abuses, but they always deny the charges.
Nigeria has recently intensified a crackdown on separatist agitators, including the arrest and trial of their leaders.
Last month, IPOB leader and founder Nnamdi Kanu was arrested in Kenya, according to his lawyers, and brought back to Nigeria to face treason charges.
Kanu’s IPOB is attempting to revive the now defunct Republic of Biafra, a declaration of independence which led to a 30-month civil war between 1967 and 1970.
More than one million people, mostly Igbo, were killed in the fighting or by starvation and disease.