Battle of Ambon The Battle of Ambon ( 30 January – 3 February 1942 ) occurred on the island of Ambon in the Dutch East Indies ( Indonesia ) , during World War II . A Japanese invasion was resisted by Dutch and Australian forces . The chaotic and sometimes bloody fighting was followed by a series of major Japanese war crimes . Background . During 1941 , as the Allies perceived the possibility of war with Japan , Ambon was seen to be a strategic location , because of its potential as a major air base . The Australian government and military commanders saw that it could be used in raids on northern Australia and decided to reinforce the Dutch forces on the island . On 14 December 1941 a convoy composed of escorts " Adelaide " and " Ballarat " with the Dutch ships " Both " , " Valentijn " , and " Patras " carrying 1 , 090 troops of " Gull Force " departed Darwin and arrived at Ambon on 17 December . HMAS " Swan " escorting " Bantam " arrived with reinforcements on 12 January 1942 , remaining through raids on the 15 — 16th until the 18th . Geography . Ambon is located in the Maluku ( Moluccas ) islands , just south of the much larger island of Seram ( Ceram ) . Ambon has what might be described as a " figure eight " or " hourglass " shape , and consists of two peninsulas separated by a narrow isthmus , with long narrow bays on either side of the isthmus . The key airport at Laha is in the west of the Hitu Peninsula — northern part of the island — facing the Bay of Ambon . The town of Ambon is at the opposite side of the bay , on the southern part of the island , Laitimor Peninsula . Forces . Allies . At the outbreak of war on 8 December , Ambon was garrisoned by the 2 , 800 - strong " Molukken Brigade " of the Royal Netherlands East Indies Army ( KNIL ) garrison , commanded by Lieutenant Colonel Joseph Kapitz and consisting of Indonesia n colonial troops , under European officers . The garrison was poorly equipped and trained , partly as a result of the Netherlands having been defeated and occupied by Nazi Germany . The KNIL units were not equipped with radios and relied on landlines and written communications . They included 300 partly trained reservists . The Australian Army ' s 1 , 100 - strong Gull Force , commanded by Lt . Col . Leonard Roach , arrived on 17 December . The force consisted of the Australian 8th Division ' s 2 / 21st Infantry Battalion , as well as some divisional artillery and support units . Kapitz was appointed Allied commander on Ambon . Roach had visited the island before Gull Force ' s deployment and requested that more artillery and machine gun units be sent from Australia . On 6 January , after Dutch and British territories to the north fell to Japan , Ambon came under attack from Japanese aircraft . Roach complained about the lack of response to his suggestions , and as a result he was replaced by Lt . Col . John Scott on 14 January . Kapitz ' s headquarters was at Halong , between Paso and the town of Ambon . It included four armoured cars , an anti - aircraft machine gun detachment and four 40 mm AA guns . In the belief that the terrain on the south coast of Laitimor was too inhospitable for landings and that any attack was likely to be in the east , around the Bay of Baguala , the KNIL forces were concentrated at Paso , near the isthmus , under Major H . H . L . Tieland . There were small KNIL detachments at likely landing places in the north of Hitu . Two companies of the 2 / 21st Battalion and 300 Dutch troops were at Laha airfield , under the command of Major Mark Newbury . They were accompanied by Dutch artillery : four 75 mm field artillery pieces , four 37 mm anti - tank guns , four 75 mm AA guns , four 40 mm AA guns , a AA machine gun platoon and a AA machine gun battery . However , Lt Col . Scott , Gull Force HQ and the remainder of the Australian troops were concentrated in the western part of Laitimor Peninsula , in case of an attack from the Bay of Ambon . " A " Company of the 2 / 21st and one KNIL company were stationed at Eri , on the south west side of the bay . The 2 / 21st Battalion ' s pioneer platoon was on the plateau around Mt Nona ( the highest point on Laitimor ) , with a Dutch anti - aircraft machine gun detachment . Smaller Australian detachments were at : Latuhalat , near the south western tip of Laitimor and at Cape Batuanjut , just north of Eri . Gull Force HQ and a strategic reserve , " D " Company , were located on a line from the Nona plateau to Amahusu beach , between Eri and the town of Ambon . The Allies had few aircraft to spare . The KNIL Air Service sent No . 2 Flight , Group IV ( " 2 - Vl . G . IV " ) from Java to Laha . Of an original four Brewster Buffalo s , two crashed en route to Ambon . The Royal Australian Air Force sent two flights , comprising 12 Lockheed Hudson Mk 2 light bombers , from No . 13 and No . 2 Squadrons , were deployed to the area , under Wing Commander Ernest Scott ( who was not related to Lt Col . John Scott ) . One flight was based at Laha , and another was sent to Namlea on the neighbouring island of Buru . The U . S . Navy ’ s Patrol Wing TEN , with PBY Catalinas , based at the Halong seaplane station from 23 December . Wing Headquarters moved to Java 9 January , but American PBYs mounted patrols from Halong through the 15 January air raid , and then abandoned the base as too exposed . Altogether five USN PBYs were destroyed there by air attack . The Wing ’ s seaplane tenders supported patrols , but left after 8 January . Tender - based patrols from William B . Preston ( AVD 7 ) and Heron ( AVP 2 ) at anchorages further south continued until 5 February . The Royal Netherlands Naval Air Service / Marineluchtvaartdienst flew patrols from Ambon / Halong ; GVT 17 with Catalina flying boats continued from the start of war through 14 January , when they were ordered to Java . U . S . Navy and RAAF aircraft made several very dangerous evacuation flights into Ambon / Laha in the last days of January . " Gouden Leeuw " , a Royal Netherlands Navy minelayer , left Ambon in early January , after mining approaches to the island . By mid - January , " Heron " was the only Allied combat ship at Ambon . Japan . An Imperial Japanese Navy ( IJN ) task force for the invasion of Ambon , commanded by Rear Admiral Ibō Takahashi , included the aircraft carrier s " Hiryū " and " Sōryū " , two seaplane tender s , the heavy cruiser s " Nachi " and " Haguro " , the light cruiser " Jintsu " , 15 destroyer s , five minesweeper s , four submarine chaser s and two patrol boat s . The Japanese ground forces were made up of about 5 , 300 personnel : the Itō Detachment of the Imperial Japanese Army ( IJA ) , under Major General Takeo Itō , comprising the 38th Division HQ and the 228th Infantry Regiment , along with marine s from the 1st Kure Special Naval Landing Force ( part of the China Area Fleet ) , under Rear Admiral Koichiro Hatakeyama . Battle . 30 January . From 6 January onwards , Ambon was attacked by Japanese aircraft . Allied aircraft made some sortie s against the approaching Japanese fleet , with little success . On 13 January , the two Buffalos , piloted by Lt Broers and Sgt Blans , attacked a flight of 10 Zero fighter s . Broers ' plane was hit and caught fire , but he continued to attack until it became uncontrollable , at which point he abandoned the Buffalo , using his parachute and landed in the sea . Blans was also shot down but also managed to use his parachute , landing in trees on Ambon . Both men were rescued . Broers suffered severe burns and Blans had 17 different wounds . The naval aviation base at Halong was soon rendered unusable by Japanese air raids , and was abandoned by the Dutch and US navies in mid - January . On 30 January , about 1 , 000 Japanese marines and IJA personnel landed at Hitu - lama on the north coast . Other elements of the 228th Regiment landed on the southern coast of the Laitimor Peninsula . Although the Japanese ground forces were numerically not much bigger than the Allies , the Japanese had overwhelming superiority in air support , naval and field artillery , and tanks . The remaining Allied aircraft were withdrawn that day , although RAAF ground staff remained . Within a day of the Japanese landings , the Dutch detachments in their vicinity were overrun and / or had withdrawn towards Paso . The destruction of bridges on Hitu was not carried out as ordered , hastening the Japanese advance . There was a second wave of landings , at Hutumori in south eastern Laitimor , and at Batugong , near Paso . An Australian infantry platoon was detached to reinforce the pioneers on Nona plateau . The defences at Paso had been designed to repel attacks from the north and west , and now faced assault from the south . A KNIL platoon was detached from Paso to resist the attack on Batugong , causing a gap in the Dutch lines . The Japanese took advantage of this , and were assisted by the failure of a KNIL telephone line . 31 January . Batugong fell in the early hours of 31 January , enabling the Japanese to encircle the eastern flank of the Passo positions . Meanwhile , Kapitz ordered the Ambonese KNIL company at Eri to take up a position at Kudamati , which appeared prone to attack . At noon on 31 January , Kapitz moved his headquarters from Halong to Lateri , closer to Passo . Telephone communications between Kapitz and his subordinates , including Lt Col . Scott , ceased when the Japanese cut the lines . The Japanese force which had landed at Hitu - Lama then attacked the Passo defences from the north - east . Then , in the words of the Australian official historian : It is not clear who authorised the surrender . There was no immediate response from the Japanese , and — in a meeting with company commanders — Kapitz and Tieland ordered the Dutch troops to recommence fighting . However , when Tieland and the company commanders returned to their positions , they found that their troops had been taken prisoner , and they were forced to surrender . The first land attack on Laha occurred on the afternoon of 31 January . An Australian platoon north - east of the airfield was attacked by a stronger Japanese force , which it repelled . Japanese forces were also approaching the town of Ambon from the south west . At about 4 p . m . on 31 January , the Japanese captured the town , including an Australian casualty clearing unit . 1 February . Several Japanese attacks were launched simultaneously on 1 February : The Australian positions were also receiving large numbers of Dutch personnel fleeing from Paso . At 10 : 30 p . m . , Scott ordered a withdrawal of the Allied forces at Amahusu and the south west , to Eri . The position at Kudamati was effectively encircled . 2 – 3 February . On 2 February ( some sources say 1 February ) , the Japanese minesweeper " W - 9 " struck a mine laid by the Dutch minelayer " Gouden Leeuw " in the Bay of Ambon and sank . Two other Japanese minesweepers were also damaged by mines . After dawn on 2 February , the main Australian force on Nona plateau , commanded by Lieutenant Bill Jinkins , was in danger of encirclement . Jinkins ordered a withdrawal to Amahusu , where he became aware that the Dutch had surrendered . Unable to ascertain the disposition of Lt Col . Scott ' s force , Jinkins decided to meet senior Japanese officers under truce at the town of Ambon . They allowed him to speak to Kapitz , who wrote another note advising the Australian commander to surrender . Jinkins set off to find Lt Col . Scott . Meanwhile , the Japanese forces attacking Laha were reinforced and a concentrated assault on the Allies began , including naval artillery , dive bombers , fighter planes and probing attacks by infantry . A Japanese night attack in high grass near the beach , between two Allied positions , was beaten back by an Australian platoon . However , a massive Japanese offensive commenced at dawn on 2 February . By 10 a . m . , only about 150 Australians and several KNIL personnel were still able to fight at Laha , and Newbury ordered them to surrender . By the morning of 3 February , the Australians around Eri were struggling to cope with increasing air and naval attacks , wounded Australians , the influx of Dutch personnel , diminishing supplies and widespread fatigue . A Japanese flag had been seen flying on the other side of the bay , at Laha . By the time Jinkins reached Lt Col . Scott , the latter had himself met the Japanese and decided to surrender . The Allied position at Kudamati was surrendered separately at midday . Laha massacre . Allied casualties in the battle were relatively light . However , at intervals for a fortnight after the surrender , IJN personnel chose more than 300 Australian and Dutch prisoners of war at random and summarily executed them , at or near Laha airfield . In part this was revenge for the sinking of the Japanese minesweeper , as some surviving crew of the minesweeper took part . Those killed included W / Cdr Scott and Maj . Newbury . According to an Australian War Memorial principal historian , Dr Peter Stanley , over the following three and a half years , the surviving POWs : In 1946 , incidents which followed the fall of Ambon became the subject of one of the largest ever war crimes trials : 93 Japanese personnel were tried by an Australian military tribunal at Ambon . R . Adm Hatakeyama was found to have ordered the Laha massacres , however he died before he could be tried . Commander Kunito Hatakeyama , who was in direct command of the massacres , was sentenced to execution by hanging . Lieutenant Kenichi Nakagawa was sentenced to 20 years imprisonment . Three other Japanese officers were executed for mistreatment of POWs and / or civilians on other occasions , during 1942 – 45 . ( The trials were the basis for the feature film " Blood Oath " , released in 1990 . ) General Itō was sentenced to death that same year for war crimes committed in other parts of the Pacific . Other subsequent events . Approximately 30 Australian soldiers , including Jinkins , escaped from Ambon , in the space of several weeks after the surrender , often by rowing prahu s ( canoes ) to Seram . Another result of the capture of Ambon was the realisation of Australian fears of air attacks , when Japanese planes based at Ambon took part in major air raids on Darwin , Australia on 19 February .