Abuja: Nigerian army and radical Islamist sect Boko Haram fighting each other across the nation`s northern region might have committed crimes against humanity by torturing and killing civilians, a rights watchdog said in a report Thursday.
Human Rights Watch (HRW) said Boko Haram and soldiers fighting to eliminate them might have committed crimes against humanity since the commencement of the fighting in 2009.
HRW estimated that hostilities between Boko Haram and military unit called Joint Task Force (JTF) have killed no fewer than 2,800 persons in the past three years.
The report titled `Spiralling Violence: Boko Haram Attacks and Security Force Abuses in Nigeria` catalogues atrocities for which Boko Haram has claimed responsibility.
It also explores the role of Nigeria`s security forces, whose own alleged abuses contravene international human rights law and might also constitute crimes against humanity.
It documents several allegations of abuses committed by the sect such as the mass murder of Christians, assassination of Islamic clerics and killings of civilians.
"The unlawful killing by both Boko Haram and Nigerian security forces only grows worse; both sides need to halt this downward spiral," said Daniel Bekele, Africa director at HRW.
"Nigeria`s government should swiftly bring to justice the Boko Haram members and security agents who have committed these serious crimes."
HRW researchers interviewed 135 people, including 91 witnesses and victims of Boko Haram violence or security forces abuses, as well as lawyers, civil society leaders, government officials, senior military and police personnel.
Since 2009, hundreds of attacks by suspected Boko Haram members have left more than 1,500 people dead, according to media reports monitored by the watchdog.
In the first nine months of 2012 alone, more than 815 people died in some 275 suspected attacks by the group - more than in all of 2010 and 2011 combined.
Boko Haram, which means "Western education is a sin" in the Hausa language of northern Nigeria, seeks to impose a strict form of Sharia or Islamic law in northern Nigeria.
Widespread poverty, corruption, police abuse and longstanding impunity for a range of crimes have created a fertile ground for violent militancy in the oil-rich African country, Human Rights Watch said.
HRW noted that Nigeria`s government has responded to Boko Haram with a heavy hand. 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.
But the authorities have rarely prosecuted those responsible for the Boko Haram violence or security force personnel for their abuses.