In March 1944, a force of three Imperial Japanese Navy (IJN) heavy cruisers raided Allied shipping in the Indian Ocean, the codename of this operation was Operation SA No.1. The cruisers departed Japanese-held territory on 1 March with the support of other IJN vessels and aircraft. On 9 March, they encountered and sank the British steamer Behar, with the heavy cruiser Tone picking up over 100 survivors. Fearing detection, the Japanese force subsequently returned to the Netherlands East Indies (NEI), arriving on 16 March. Two days later, most of Behar's crew and passengers were murdered on board Tone. Following the war the commander of the raid, Rear Admiral Naomasa Sakonju, was executed for this war crime and Tone's captain Haruo Mayuzumi was sentenced to seven years imprisonment.

Tone (利根) was the lead ship in the two-vessel Tone class of heavy cruisers in the Imperial Japanese Navy. The ship was named after the Tone River, in the Kantō region of Japan and was completed on 20 November 1938 at Mitsubishi's Nagasaki shipyards. Tone was designed for long-range scouting missions and had a large seaplane capacity. She was extensively employed during World War II usually providing scouting services to their aircraft carrier task forces. She almost always operated in this capacity in conjunction with her sister ship Chikuma.