An independent commission of UN war crimes investigators have denounced a “staggering loss of civilian life” that has resulted from the escalation of US airstrikes against the ISIS-held city of Raqqa since the beginning of the Kurdish invasion of the city last week.

The Kurdish YPG has been advancing on Raqqa for months, and the US airstrikes in the course of that operation have killed a lot of civilians too, but its grown precipitously in thepast week, and the UN inquiry said US airstrikes in Raqqa had killed at least 300 civilians.

Paulo Pinheiro, the head of the UN commission of inquiry, warned the escalation of the US airstrikes had not only killed hundreds of people, but had also led to the displacement of 160,000 civilians from in and around the city, adding to the ever-growing problem of internally displaced persons within Syria.

Pinheiro went on to say that the US should not allow its fight against terrorism to be “undertaken at the expense of civilians.” Given how many civilians were killed in the course of the US airstrikes in Iraq’s invasion of Mosul, however, killing large numbers of civilians in increasingly par for the course in US operations inside large cities.

Human Rights Watch also chimed in, faulting the US for the use of toxic incendiary white phosphorus inside the city, saying it was unacceptable to use the chemical in populated areas, and that the US should show more care with such attacks.