Iraqi civilians are being subjected to “barbaric” sexual violence committed by Sunni Islamic State (IS) jihadist fighters, the U.N reports.

Two U.N. officials say they’ve received accounts of “barbaric acts” of sexual violence including “savage rapes” being used as weapons of war against women and teenage girls and boys belonging to the Yazidi, Christian, Turkomen and Shabak minority groups in Iraq. As many as 1,500 Yazidis and Christians may have been forced into sex slavery and human trafficking, the UN reports.

“We condemn, in the strongest terms, the explicit targeting of women and children and the barbaric acts the ‘Islamic State of Iraq and the Levant’ has perpetrated on minorities in areas under its control, and we remind all armed groups that acts of sexual violence are grave human rights violations that can be considered as war crimes and crimes against humanity,” Nickolay Mladenov, special representative of the U.N. secretary-general for Iraq, and Zainab Hawa Bangura, special representative of the secretary-general on sexual violence in conflict, said in a joint statement issued from Baghdad.
 
The UN warned on Tuesday that Yazidis are on the brink of an imminent mass genocide at the hands of IS. The United Nations Refugee Agency (UNHCR) estimates 20,000 to 30,000 Yazidis remain trapped in searing temperatures on top of Mount Sinjar in northwest Iraq with little food, water or medical supplies. The Yazidis  — a majority Kurdish-speaking religion that combines elements of Christianity, Islam and the ancient Persian faith Zoroastrianism —  were trapped after fleeing IS militants who issued them an ultimatum: convert to Islam or die.

The U.S. and France are both stepping up efforts to relieve the plight of Iraq’s Yazidis, who IS consider to be devil worshippers, and other religious minority groups. The U.S. is sending 130 “advisers” into northern Iraq to help assist in the evacuation of the thousands of Yazidis still stranded on the mountain. The Defense Department emphasized that the advisers, all Marines and Special Operations forces, won’t be used in combat roles but will plan and perhaps carry out the evacuation of Yazidis. The addition of 130 advisers brings the total number of U.S. military personnel in Iraq to more than 1,000, The New York Times reports.

The U.S. has also been airdropping food, water and medical supplies over the past six days to Yazidis who remain trapped on Mount Sinjar. However, the airdrops are not seen as a sustainable solution to the crisis, said Ben Rhodes, U.S. deputy national security adviser. Instead, the creation of a safe corridor or airlifts for fleeing minorities are being considered. U.S. Secretary of State John Kerry said he is “assessing” the best way to get the Yazidis off the mountain, The New York Times reports.

French President François Hollande said on Wednesday that France will supply arms to the Kurdish peshmerga forces to repel Islamic State (IS) militants and prevent them from advancing on Erbil, the capital of the Kurdish semi-autonomous region. The U.S., which has already carried out airstrikes targeting IS fighters, will also directly arm the Kurdish peshmerga forces.

“In order to respond to the urgent needs expressed by the Kurdistan regional authorities, the president has decided, in agreement with Baghdad, to deliver arms in the next few hours,” Hollande said in a statement from his office.

The United Kingdom agreed to send helicopters to Iraq to “aid surveillance of the zone where the refugees are trapped,” The Independent reports.