At least 250 US-led air strikes have pounded the Syrian city of Raqa and surrounding territory in the past week, the coalition fighting ISIS group said.
Coalition spokesman Colonel Ryan Dillon told AFP that the air raids targeted the greater Raqqa area.
Activists and monitoring groups have reported that intensifying coalition bombardment of the city has left scores of civilians dead.
Earlier 42 civilians were reported killed Monday in a barrage of US-led air strikes on ISIS territory in the Syrian city of Raqqa, a monitor said.
Nineteen children and 12 women were among those killed in the raids, which hit several neighborhoods in the northern city, the Syrian Observatory for Human Rights told AFP on Tuesday.
The toll marked the second consecutive day of ferocious bombardment on Raqqa, more than half of which has been captured by the US-backed Syrian Democratic Forces battling ISIS.
The latest figures for Monday’s raids take to 167 the number of civilians killed in coalition strikes since August 14, after the Observatory said at least 27 were killed on Sunday.
“The tolls are high because the air strikes are hitting neighborhoods in the city centre that are densely packed with civilians,” said Observatory director Rami Abdel Rahman. “There are buildings full of civilians that are trying to get away from the front lines.
“Coalition air strikes are targeting any building where any kind of Daesh movements are being detected,” he told AFP, using an Arabic acronym for ISIS.
The United Nations estimates there are up to 25,000 civilians trapped inside the city, with food and fuel supplies short and prohibitively expensive.
Raqqa “worst place”
The UN’s humanitarian point man for Syria, Jan Egeland, has said ISIS-held territory in Raqqa city is now “the worst place” in the war-torn country.
More than 330,000 people have been killed in Syria’s conflict, which began with anti-government protests in 2011 but has since mushroomed into all-out war drawing in world powers.
The US-led coalition, which operates in both Syria and neighboring Iraq, says it takes all possible measures to avoid civilian casualties.
In August, it acknowledged the deaths of 624 civilians in its strikes in Syria and Iraq since 2014, but rights groups say the number is much higher.