According to some sources Jews, together with Roma and Communists, were sent into mine fields, where they were killed when the mines exploded.
Related Resources
ChGK Soviet Reports
The ChGK report from Bryansk
Numerous witnesses testified that the Germans caught Jews, Gypsies, and Communists, tied them to poles 0.5 – 2 meters from each other, and forced them into mine fields where the doomed ones set off the mines.