SEOUL, South Korea  North Korean doctors perform operations without anesthesia in clinics where hypodermic needles are not sterilized and sheets are not washed, the human rights group Amnesty International said in a report released on Thursday.

“Five medical assistants held my arms and legs down to keep me from moving,” the report quoted a 24-year-old North Korean defector as saying, describing how his left leg was amputated without anesthesia after a train accident. “I was in so much pain that I screamed and eventually fainted from pain.”

Other defectors told similarly horrific stories. One said her appendix was removed without anesthesia and her hands and feet were bound to prevent her from moving during the procedure. Others told of entire cities with no ambulances.

Drawn from interviews with more than 40 North Koreans who had defected over the past six years, as well as with health professionals who had worked with North Koreans, the report depicted a North Korean health system in dire straits.