BEIRUT: The U.S.-led coalition's reliance on imprecise and disproportionately powerful ordnance in its campaign against Daesh (ISIS) militants in the Syrian city of Raqqa is exacting a significant toll on civilians, Amnesty International said in a report on Thursday.

The watchdog also criticizes the coalition for failing to properly investigate reports of hundreds of civilian casualties in the campaign, which began in June.

Coalition spokesman Col. Joe Scrocca dismissed Amnesty's report, saying it is based on "scant information" and plays into the hands of the militants.

As the fight for Raqqa intensifies, "thousands of civilians are trapped in a deadly labyrinth where they are under fire from all sides," said Amnesty researcher Donatella Rovera who led a week-long investigation in late July into the Raqqa offensive.

Amnesty's team documented 95 civilian deaths, including 41 children and 25 women, in June and July because of the U.S.-led campaign. Amnesty said it interviewed dozens of civilians, humanitarian and medical personnel and others.

The report said civilians also come under fire from the Russia-backed Syrian government forces fighting IS militants to the south of Raqqa. At least 30 civilians were killed in that campaign, it said. At the same time, IS militants use civilians as human shields and hide among them from advancing forces, the group said.

Amnesty said the United States has been providing artillery support, using Howitzers which fire 155 mm shells and GPS-directed 227 mm mortars, for the Kurdish-led Syrian forces it backs on the ground. The local forces are armed with 120 mm mortars.

"Coalition forces' reliance to a large extent on weapons which have a wide impact radius and which cannot be accurately pinpointed at specific targets to neutralize IS targets in civilian neighborhoods has exacted a significant toll on civilians," the report said. Resident testimonies indicate the missiles have targeted areas of hundreds of square meters, rather than specific targets "which, if true, would constitute not only disproportionate but also indiscriminate attacks."

The report also said that the coalition's use of airstrikes, while more accurate than artillery fire, has often hit civilians at home or while they attempted to flee.

Scrocca, the spokesman, said the coalition is doing "everything within our power" to limit harm to non-combatants and civilian infrastructure. He said the militants have for years prepared for the defense of Raqqa, so a house-to-house and street-by-street battle is inevitable.

"The unfortunate death of civilians is a fact of war that weighs heavy on our hearts, however, if (IS) is not defeated the cost will be even higher, and it will be paid not just in Iraq and Syria, but in our homelands across the globe," Scrocca told The Associated Press in an email.

Amnesty criticized the coalition for "poor reporting and inadequate investigation" of civilian casualties, saying they lack basic information on weapons deployed or visits to sites of attacks.

In its three-year campaign in Syria and Iraq, the coalition says it can verify 624 unintentional civilian deaths.