Coalition air strikes in Syria and Iraq fell sharply last month, a reflection of the collapse of the Islamic State group, a US Air Force general said Tuesday.

Brigadier General Andrew Croft, who coordinates the coalition air campaign, said there were 60 to 70 percent fewer air strikes in October than the average for the preceding eight to nine months.

"That's indicative of the fact that ISIS is collapsing not only as a physical caliphate but also in ownership of land," he told reporters in a teleconference.

"They only control about four or five percent of the original area they covered, so the number of targets has dropped dramatically, particularly in the last month."

He said 850 bombs were dropped during October compared to 1,800 to 2,400 a month since the start of the year.

The decline came in the same month that Raqa, IS's Syrian stronghold, fell to US-backed Kurdish forces.

Before that, Iraqi forces backed by coalition airpower retook the northern city of Mosul from IS in early July.

According to coalition estimates, at least 786 civilians have been killed during the three-year air campaign against the Islamic State group in Iraq and Syria.

Airwars.Com, a website that monitors casualty reports, puts the number of civilians killed in coalition airstrikes at nearly 6,000.

Souece: AFP