The International Criminal Court's prosecutor has accused Boko Haram militants of committing crimes against humanity in Nigeria, mainly murder and persecution.
The office of prosecutor Fatou Bensouda says there is a "reasonable basis" to believe Boko Haram has launched a "widespread and systematic attack" that resulted in the deaths of more than 1,200 Christians and Muslims since mid-2009.
Boko Haram Facts
Based in the northeastern city of Maiduguri
Began in 2002 as a non-violent Islamist splinter group
Launched uprising in 2009; leader was subsequently killed in police custody
Has killed hundreds in bombings and shootings since 2010
Boko Haram translates to "Western education is sinful"
Wants Nigeria to adopt strict Islamic law
Says it will kidnap women and children as part of its campaign
Has taken over parts of northeastern Nigeria
The report, which was leaked to media outlets, recommends that Nigerian authorities prosecute those crimes, or the ICC could do it itself.
Regarding accusations that Nigerian security agencies also committed human rights violations, the report said there is no indication that those alleged acts were part of a "state or organizational policy to attack the civilian population."
Last month, Human Rights Watch said the conflict between Boko Haram and the Nigerian government has claimed more than 2,800 lives since 2009, with some 1,300 the result of action by Nigerian security forces.
The group said the violence escalated this year, with more than 815 killings in the first nine months alone.
Boko Haram says it is fighting to establish an Islamic state in northern Nigeria.