The Kempeitai ran extensive criminal and collaborationist networks,
extorting vast amounts of money from businesses and civilians wherever they operated. They also ran the Allied prisoner of war system, which
often treated captives with extreme brutality...
The Kempeitai also carried out revenge attacks against prisoners and civilians. For example, after Colonel Doolittle's raid on Tokyo in 1942, the Kempeitai carried out reprisals against thousands of Chinese civilians and captured airmen... All these actions together amounted to
genocide on a gigantic scale, and—including Unit 731's vivisection campaign—
some of the worst atrocities committed during World War II
https://en.wikipedia.org/wiki/Kempeitai