Dozens of Yazidi women and girls abducted by members of terror group Islamic State (Isis) are committing suicide to escape sex slavery, a rights group has warned.

The Yazidis, a Kurdish ethno-religious community whose religion combines elements of Zoroastrianism with Sufi Islam, have been persecuted by the militants, who have vowed to carry out ethnic cleansing against non-Arabs and non-Sunni Muslims in Iraq and Syria.

According to the latest report by Amnesty International, Yazidi women and girls as young as 10 are systematically abducted, raped, tortured and sold at slave markets, which the insurgents often use to lure potential fighters.

"Hundreds of Yazidi women and girls have had their lives shattered by the horrors of sexual violence and sexual slavery in IS captivity," said Donatella Rovera, Amnesty International's senior crisis response advisor, who spoke to more than 40 former captives in northern Iraq.

"Many of those held as sexual slaves are children – girls aged 14, 15 or even younger. IS fighters are using rape as a weapon in attacks amounting to war crimes and crimes against humanity."

One of the girls who was held in the same room with other captives, including two girls aged 10 and 12, told Amnesty International: "One day we were given clothes that looked like dance costumes and were told to bathe and wear those clothes. Jilan [one captive] killed herself in the bathroom. She cut her wrists and hanged herself.

"She was very beautiful; I think she knew she was going to be taken away by a man and that is why she killed herself."

In October, a Yazidi woman held captive in a brothel in Iraq managed to contact members of NGO Compassion4Kurdistan and told them she was raped around 30 times a day by the insurgents.

In the same month, IS members admitted they are kidnapping hundreds of Yazidi women and forcing them into sex slavery.

Amnesty's report came a few days after Germany announced its plan to open a trauma centre to assist women and girls who were sexually abused by the militants.

The decision was put forward by Development Minister Gerd Müller after he had travelled to Iraq and met with women who were raped by IS members.