Question: What unit was directed by Shiro Ishii and based at the Pingfang district of Harbin?
Sentence (from "Shirō Ishii"): Surgeon General Shirō Ishii (石井 四郎 , Ishii Shirō , ; June 25, 1892 – October 9, 1959) was a Japanese army medical officer, microbiologist and the director of Unit 731, a biological warfare unit of the Imperial Japanese Army involved in forced and frequently lethal human experimentation during the Second Sino-Japanese War (1937–1945).
Relevant evidence: Yes