Sobibór was a Nazi extermination camp that was part of Operation Reinhard. Jews, Soviet POWs, and possibly Gypsies were transported to Sobibór by rail, and suffocated in gas chambers that were fed with the exhaust of a diesel motor. About 260,000 people were killed in Sobibór.

External link

http://auschwitz.dk/Sorbibor.htm contains a description of Sobibór.