Allied submarines harassed Japanese controlled Saigon shipping according to the U.S. Joint Intelligence Committee Daily summary dated 11 May 1942

An item reported that the Japanese controlled the Saigon shipping in French-Indochina but which was harassed by Allied submarines.

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. U.S. Joint Intelligence Committee. Daily summary No. 152 dated 11 May 1942