The Boko Haram sect might have committed crimes against humanity during three years of conflict that has killed at least 2,800 people, Human Rights Watch (HRW) said yesterday.
Crimes against humanity are offences that can lead to prosecution by the International Criminal Court (ICC).
The group, in a statement released yesterday, said the insurgents and security forces have both engaged in unlawful killings which have only fuelled the violence.
The report documents multiple cases of abuses by Boko Haram, including brutal killings of Christians and Muslims who criticise them.
Some of these attacks were "deliberate acts leading to population 'cleansing' based on religion or ethnicity."
The report also accused the military and police joint taskforce (JTF) of "physical abuse, secret detentions, extortion, burning of houses, stealing money during raids, and extrajudicial killings of suspects."
It called on the government to cease the use of force and highhandedness in handling repeated attacks by Boko Haram and concentrate on prosecuting offenders who have been arrested.
It said security forces have killed hundreds of Boko Haram suspects and other members of the public with no apparent links to the group, in the name of ending the group's threat to the country's citizens.
Asked about the report, Lieutenant Colonel Sagir Musa, JTF spokesman for Borno State, reiterated a statement on Wednesday that there was no evidence of such abuses. There was no immediate reaction from Boko Haram.
With Agency Report