Following the defeat of the Japanese surface fleet the IJN deployed submarines to disrupt Allied supply lines by attacking shipping off the Australian east coast. This campaign began with an unsuccessful midget submarine raid on Sydney Harbour on the night of 31 May 1942. Following this attack, Japanese submarines operated along the Australian east coast until August 1942, sinking eight merchant ships. The submarine offensive resumed in January 1943 and continued until June during which time a further 15 ships were sunk off the east coast. The 1943 sinkings included the hospital ship , which was torpedoed off Queensland on 14 May with the loss of 268 lives. The Japanese did not conduct further submarine attacks against Australia after June 1943, as their submarines were needed to counter Allied offensives elsewhere in the Pacific. A single German submarine, , operated in the Pacific Ocean during the war, cruising off the Australian coast and New Zealand in December 1944 and January 1945. It sank two ships in Australian waters before returning to Batavia.