United Nations Human Rights Chief Zeid Al-Hussein urged the Nigerian government to allow Boko Haram rape victims to have abortions.

"Interviews have confirmed that during their [Boko Haram militants] captivity—lasting in many cases for months or even years—women and girls have been sexually enslaved, raped and forced into so-called 'marriages,'" said Al-Hussein, according to the U.N. News Centre.

"Many survivors of these horrific experiences are now pregnant by their rapists," he said in a special briefing to the U.N. Human Rights Council in New York.

Human rights group Amnesty International said that Boko Haram militants have abducted more than 2,000 women and girls in northeast Nigeria since the beginning of 2014, according to AFP.

"I strongly urge the most compassionate possible interpretation of the current regulations in Nigeria to include the risk of suicide and risks to mental health for women and young girls who have suffered such appalling cruelty," said Al-Hussein, while noting that abortion is legal in Nigeria only when the life of the woman is at risk.

The U.N. rights chief's remarks come after a 12-member team visited Cameroon, southern Niger and the northeastern regions of Nigeria on Boko Haram. The report by the United Nations High Commissioner for Human Rights found violations committed by Boko Haram remain extensive and far-reaching.

"Boko Haram's pledge of allegiance to ISIS is a wake-up call. It means that another link has been added to the terrorist chain that now connects other international terrorist groups such as al-Shabab and al-Qaida," said Acting Foreign Minister of Nigeria Bulu Lolo, according to Voice of America.

The Boko Haram Islamist group killed more than 8,000 people since the militants started their attacks in Nigeria.