Islamic State has executed over 700 prisoners in eastern Syria in the past two months, the Syrian Observatory for Human Rights said Wednesday.
Citing dozens of security sources within ISIS as well as civilians living in areas under the group’s control, the Observatory said the prisoners were among a total of 1,350 civilians and fighters held by the group.
Observatory head Rami Abdul Rahman said that the executions had taken place since the United States-backed Syrian Democratic Forces had relaunched their assault on the militants in October.
Many of those killed were buried in mass graves.
ISIS also executed three more people Wednesday for “smuggling civilians” out of the enclave toward SDF-held areas, the Observatory said.
About 200 people are thought to have fled in the last 24 hours, it added. The SDF this month said that it would open up humanitarian corridors for those trying to flee the beleaguered pocket, with over 1,000 civilians reported to have escaped since Nov. 30.
With the SDF pushing deeper into Daesh territory, the militants also moved over 350 prisoners farther west of the Euphrates River, Abdul Rahman said.
The SDF, with the help of U.S. air power and special forces, has been battling ISIS in the Deir al-Zor area – the militant group’s final pocket of control in Syria – for the past several months.
Despite setbacks, the Kurdish alliance entered the strategic town of Hajin this month, clawing back territory previously lost to the extremists.
SDF Commander in Chief Mazloum Kobani told Reuters last week that at least 5,000 ISIS fighters remained holed up in the enclave, including many foreign fighters.
ISIS’s self-proclaimed caliphate at its height encompassed a third of Syria and Iraq, but has since crumbled, reducing the militants control to a small pocket in eastern Syria.