DAMASCUS (DPA) - At least 190 bodies have been recovered from a mass grave in northern Syria where Islamic State in Iraq and Syria (ISIS) militants once had their key stronghold in the country, a local official said on Wednesday (July 3).

The grave was found near the city of Raqqa, ISIS's erstwhile de facto capital in Syria.

Dozens of bodies were found in the grave of men wearing orange uniforms believed to have been killed execution-style by militants, the official at the Raqqa civil council told dpa.

The grave also contained bodies of women stoned to death and ISIS fighters, the official added on condition of anonymity.

The bodies were retrieved last month, the official said without further details.

"This grave is part of a series of graves located in the area of the Vanguard Camp where more than 3,500 bodies have been recovered over the past months," he said.

The Vanguard Camp, about 5km south-west of Raqqa, was a site where ISIS trained children in fighting.

In October 2017, a Syrian Kurd-led militia, supported by the United States, captured Raqqa from ISIS in a major blow to the radical group.

Syria's Kurds played a key role in defeating ISIS in Syria.