Intensified coalition air strikes supporting an assault by US-backed rebel forces on Raqqa, Syria, are causing a "staggering loss of civilian life", United Nations war crimes investigators have said.
The Syrian Democratic Forces (SDF), a group of Kurdish and Arab militias supported by a US-led coalition, began attacking Raqqa a week ago to take it from the Islamic State of Iraq and the Levant (ISIL, also known as ISIS).
Paulo Pinheiro, chairman of the UN Commission of Inquiry, told the Human Rights Council on Wednesday that the increased attacks have resulted "not only in staggering loss of civilian life", but have also "led to 160,000 civilians fleeing their homes".
Pinheiro did not provide a figure for civilian casualties in Raqqa, where rival forces are racing to capture ground from ISIL.
The SDF, supported by heavy coalition air strikes, have taken territory to the west, east and north of the city.
The Syrian army is also advancing on the desert area west of the city.
Residents, as well as the campaign group Raqqa is Being Silently Slaughtered and the Syrian Observatory for Human Rights war monitor, also say air strikes have killed significant numbers of civilians.
Pinheiro said that if the international coalition's offensive was successful, it could liberate Raqqa's civilian population, including Yazidi women and girls, "whom the group has kept sexually enslaved for almost three years as part of an ongoing and unaddressed genocide".
But it must not be at the expense of civilians who unwillingly find themselves in areas where ISIL is present, he cautioned.
Pinheiro also said that 10 agreements between the Syrian government and armed groups to evacuate fighters and civilians from besieged areas, including eastern Aleppo last December, "in some cases amount to war crimes" as civilians had "no choice".
Separately, the Human Rights Watch (HRW) has expressed concern over the use of incendiary white phosphorus weapons by the US-led coalition fighting ISIL, after reports that such weapons were used in Raqqa on Thursday.
While international law permits the use of white phosphorus to cover troop movements, HRW in a statement said the chemical's use in crowded cities such as Raqqa "poses a high risk of horrific and long-lasting harm".
The global human rights group said white phosphorus can start fires and cause excruciating burns for bystanders.
The US military refused to comment on specific allegations, but said it uses white phosphorus lawfully.
The US delegation, in its speech to the Human Rights Council in Geneva, called the Syrian government "the primary perpetrator" of egregious human rights violations in the country, but made no reference to Raqqa or the air strikes.
Syria's ambassador to the UN in Geneva, Hussam Edin Aaala, denounced violations "committed by the unlawful US-led coalition which targets infrastructure, killing hundreds of civilians".
Source: Reuters news agency