US BOMBING of targets in Iraq and Syria has killed hundreds of civilians, a monitoring group said yesterday, potentially boosting support for Islamic State (Isis).

The report by Airwars, a project to monitor the campaign of air strikes by the US-led coalition — a year old this week — detailed 57 specific attacks that it believed had killed up to 591 civilians and caused 80 suspected “friendly-fire” deaths among Western-backed militant groups.

“Almost all claims of non-combatant deaths from alleged coalition strikes emerge within 24 hours, with graphic images of reported victims often widely disseminated,” the report said.

“In this context, the present coalition policy of downplaying or denying all claims of non-combatant fatalities makes little sense and risks handing Islamic State and other forces a powerful propaganda tool.”

But the bigger picture — as shown on the group’s website — is that up to 1,247 civilian deaths have resulted from almost 6,000 air strikes since last August, some 2,300 of which have targeted Syria.

The tempo of operations has also increased, from 120 raids a month to about 850.

Like the better-known Iraq Body Count website, Airwars relies on media reports of casualties from air strikes, so may underestimate the true death toll.

Airwars said that it had looked into more than 1,000 claims of civilian casualties since February, adding that it had discounted many of them.

While the monitors noted the difficulty of verifying information in territory held by Isis, other groups have reported similar casualties from the US-led attacks.