According to US Army historian John Miller, Allied intelligence estimated the strength of Japanese forces on Bougainville and the nearby islands were "37,500 soldiers and 20,000 sailors", while US Marine historians Henry Shaw, Douglas Kane and John Rentz, variously provide estimates of between 35,000 and 44,000 Japanese troops on Bougainville. The main concentrations of Japanese troops were estimated as follows: 17,000 in the southern part of the island; 5,000 around Buka, in northern Bougainville; 5,000 around Kieta on the eastern coast; 5,000 to 6,000 on the Shortland Islands; 3,000 in the vicinity of Ballale; and about 1,000 at Mosigetta, which was about inland from the southern end of Empress Augusta Bay. The 20,000 naval personnel were based in southern Bougainville where they formed part of Vice Admiral Tomoshige Samejima's 8th Fleet. These estimates were based on Ultra, augmented by documents captured in the Central Solomons, and by interrogation of prisoners of war. Post war, Japanese sources have indicated that Allied estimates of Japanese strength were close.