A UK-based monitoring group has announced that at least 744 civilians have been killed in US airstrikes in Iraq and Syria last month.

On Wednesday, Airwars, a London-based independent group of researchers and journalists, stressed that the number of concurrent airstrikes on Raqqah in Syria and Mosul in Iraq was "devastating."  

The toll is subsequently higher than the 603 civilians the US military claims were killed since it began its anti-terror operations in the region in 2014.

Airwars Director Chris Woods stressed that the US’ goal of "annihilation" of Daesh terrorists is placing civilians at a high level of risk.

Airwars noted that between 529 and 744 of the civilians were killed in June, which marks a 50-percent increase from the previous month's tally.

"While it was always predicted that high civilian casualties would occur during the assaults on Raqqah and Mosul, this alone cannot explain the very high fatalities we and other monitors, NGOs and international agencies are tracking," said Woods.

Mosul’s liberation operation officially came to an end on Monday, with Iraqi Prime Minister Haider al-Abadi declaring victory in the city, three years after it fell to Daesh.

Operations are also underway from various fronts to liberate Raqqah, which fell to Daesh in 2014.

Bodies of civilians lie on a street in western Raqqah on July 12, 2017, during an offensive by Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab fighters, to retake the city from Daesh terrorists.  

The coalition has, time and again, been accused of disregard for civilian lives during the campaign.

Meanwhile, the Iraqi military has rejected as “baseless” an Amnesty International report accusing government forces of human rights violations during the months-long battle to liberate Mosul from Daesh terrorists.

On Wednesday, Iraq’s Joint Operations Command spokesman Brigadier General Yahya Rasool defended the performance of the Iraqi armed forces during the liberation operation, saying the Amnesty report does not reflect the realities on the ground in Mosul.  

He said the Iraqi army used light and medium arms during the offensive in Mosul, and was careful in using heavy weaponry for fear of civilian lives.