The Battle of the Malacca Strait, sometimes called the Sinking of Haguro, and in Japanese sources as the Battle off Penang (ペナン沖海戦), was a naval battle that resulted from the British search-and-destroy operation in May 1945, called Operation Dukedom, that resulted in the sinking of the Japanese cruiser Haguro. Haguro had been operating as a supply ship for Japanese garrisons in the Dutch East Indies and the Bay of Bengal since 9 April 1945.