Extermination camps were designed and built exclusively to kill prisoners on a massive scale, often immediately upon arrival.[9] The extermination camps of Operation Reinhard such as Bełżec, Sobibór and Treblinka served as "death factories" in which German SS and police murdered nearly 2,700,000 Jews by asphyxiation with poison gas, shooting, and extreme work under starvation conditions.[9][10][11]