On December 12, the media wing of the US-backed Syrian Democratic Forces (SDF) released an interview with an ISIS member, who had been captured during clashes in the area of Hajin in the Euphrates Valley. On December 13, the SDF captured the town center of Hajin and is now about to take control of entire town.
The numbers provided by the captured ISIS member in the video is apparently overestimated. However, the interview provides some interesting look at the situation within the ISIS-held area.