'Sabre' was a British naval attack on the underwater communications cables off Cape St Jacques, near Saigon in Japanese-occupied French Indo-China, using a midget submarine (31 July 1945).

The operation was a counterpart to 'Foil' off Hong Kong, and was completed successfully by XE-5 within the context of the British effort to force the Japanese to switch from cable to radio (and therefore more readily intercepted and decoded) communications between Tokyo and the southern regions of Japan’s so-called 'Greater East Asia Co-Prosperity Sphere'.