Iraqi Kurdish forces are involved in a campaign aimed at preventing the Arab population displaced by violence from returning to their homes in Kurd-controlled northern areas, Amnesty International said in a damning report.

The Kurdish Regional Government (KRG) and Peshmerga militias were one of the leading forces fighting against the onslaught of the terrorist group Islamic State (formerly ISIS/ISIL) in northern Iraq. While the Iraqi army fled the initial IS offensive, Kurds held their ground and became a principal ally for the US-led coalition fighting against the terrorists.

As fighting on the ground continued and territories in Iraq changed hands, some 3 million people were displaced. Lately the Kurds fended off IS fighters and asserted control over areas, where mixed Arab-Kurdish population lived before the violence escalated.

Now the KRG are burning and bulldozing Arab-owned homes and businesses in an apparent attempt to uproot the Arabs from those lands, Amnesty International said Tuesday in a report. The accusations are based on field investigations in 13 villages and towns, testimonies of eyewitnesses, satellite imagery and media reports. Arabs are also being barred from returning to their homes or travel freely in Kurd-controlled areas.

“KRG forces appear to be spearheading a concerted campaign to forcibly displace Arab communities by destroying entire villages in areas they have recaptured from IS in northern Iraq. The forced displacement of civilians and the deliberate destruction of homes and property without military justification, may amount to war crimes,” said Donatella Rovera, Amnesty International’s senior crisis response adviser, who carried out the field research in northern Iraq.

One of the villages mentioned in the report is Jalawla in the east of Diyala province, which has been largely destroyed, according to Amnesty. The accusations were denied by Jabbar Yawar, a spokesman for the Kurdish Peshmerga, who told the Washington Post that hundreds of families have been allowed to go back in the past two weeks.

“These are false accusations,” he said, blaming the fighting and booby traps set by IS militants for the extensive damage. “It’s normal for there to be destruction, and it was caused by Daesh,” he said, using an Arabic pejorative acronym for the terrorist group.

Amnesty said KRG officials suggested a number of justifications for what the group sees as a discriminative policy of the Kurdish authorities. Those included lack of security in some areas, alleged collaboration of the Arabs with IS and reprisal for historic injustices stemming from Saddam Hussein’s government’s effort to settle Arabs in predominantly Kurdish areas as part of demographic engineering.

The destruction of homes of Arabs is a form of collective punishment and is banned under international rules of war, Amnesty said, calling on KRG to stop this practice and pay reparations to people affected. It added that the toll taken by the violence on Kurdish population cannot excuse the abuses of Arabs.

The group called on members of the coalition, including the US, the UK and Germany, which are backing the Peshmerga forces, to condemn the violations committed by their Kurdish allies.