The graves located under a football pitch close to a hospital in the city contained bodies of both civilians and Daesh terrorists, AFP quoted Abdallah al-Eriane, a senior official with Raqqah Civil Council, as saying on Saturday, presstv.com reported.
He said up to 200 bodies could be dug up from the place upon further excavation.
"It was apparently the only place available for burials, which were done in haste,” he said, noting that the terrorists would use the hospital to hide away. Some bodies were marked with Daesh insignia, while civilians just had their first names attached to their corpses, the official noted.
Daesh attacked Syria and neighboring Iraq in 2014, overrunning vast territory in exceptionally-brutal attacks.
The United States and scores of its allies struck the Arab nations in the same year to allegedly uproot the group but never made any dependable gain against the Takfiris.
Last October, as Syria and its allies were almost defeating the group, the United States tasked the so-called Syrian Democratic Forces (SDF) militants with pushing the terrorists out of Raqqah under American air cover.
Syria and Russia have repeatedly criticized Washington for pummeling the city indiscriminately. Moscow has said the US literally “wiped Raqqah off the face of Earth” as a result of its carpet bombing campaign.
America’s aerial campaign on the Syrian city of Raqqah is drawing criticisms from Russia.
The city, Russia has said, was treated by the US military in the same way as the German city of Dresden, which was leveled to the ground in 1945.