The US-led coalition has killed nearly 500 civilians in Syria during the month of Ramadan in its military campaign against ISIS.
Around 470 civilians, including 137 children, were killed in air strikes in ISIS-held cities of Deir Ezzor and Raqqa in eastern Syria between May 23 and June 23.
The UK-based Syrian Observatory for Human Rights (SOHR) said the period saw the highest civilian death toll in US bombing campaigns for a single month since they began on 23 September 2014.
The figure has more than doubled from the previous 30-day toll.
SOHR claim the number is higher than those killed by Russian airstrikes and President Bashar al-Assad’s forces during the same period.
SOHR’s director, Rami Abdel Rahman, said that the new deaths brought the overall civilian toll from the US-coalition’s campaign in Syria to 1,953, including 333 women and 456 children.
Human rights groups have warned for months of the increasing human cost of the US-coalition’s bombing campaign, particularly as the battle for ISIS’s capital of Raqqa intensifies.
The US, Britain, France and other coalition members have provided air support for their allies Syrian Democratic Forces (SDF) on the ground.
The coalition has stated on numerous occasions that it takes vigorous precautions to avoid killing civilians, but local residents say they have become collateral damage.
In March, more than 200 mainly children and women were reported to have been killed while they sought refuge in a school in the village of Mansoura.
Shockingly high civilian death tolls are also being reported in the Iraqi city of Mosul, where the battle to defeat ISIS is in its final stages.