The 'Battle of Mindoro' was fought between US and Japanese forces for the island of Mindoro in the Philippine islands group (13/16 December 1944).
Formations and units of the US Army, supported by the US Navy and US Army Air Forces, made an amphibious landing on Mindoro and defeated the Imperial Japanese army forces garrisoning the island without meeting significant opposition from the Imperial Japanese navy and the air services of the army and the navy with the exception of kamikaze attacks on US ships. The Japanese forces on Mindoro were few in number, and eliminated in just three days by elements of the US Army assisted by guerrillas from the local Filipino population.
The US captured Mindoro in order to establish airfields that would be in fighter range of Lingayen Gulf on the western side of Luzon island, where 'Mike I', the next major amphibious invasion of the Philippine islands group, was planned. Land-based fighter cover was necessary for this operation. Mindoro could also serve as the advanced base for US earmarked for the Luzon campaign.
For the invasion of Luzon, US forces needed air bases that were closer to this northern island than Leyte island. Mindoro was the logical choice as it lies not too far south of Luzon. The island is covered mostly by hills and mountains, with a few narrow plains along its coasts. Almost daily rains and high humidity, resulting from the movement of cloud from the south and tapped by the high peaks, made the island a breeding ground for malaria and other tropical diseases.
The US airfields recently constructed at Leyte were deemed unreliable, so the possibility of additional airfields on Mindoro appealed to General Douglas MacArthur, the commanding general in this theatre of operations. The seizure of Mindoro was nonetheless a daunting task. The north-eastern coast was best suited for amphibious landings, but was exposed to what was left of Japanese air power on Luzon, so this area was ruled out of further consideration. The town of San Jose on the south-western corner, though nearer to Mangarin Bay, Mindoro’s best deep-water port, was the spot chosen by the US planners.
Lieutenant General Walter C. Krueger’s 6th Army was assigned to seize Mindoro and Krueger, in turn, gave the task to Major General Roscoe B. Woodruff’s 24th Division, with the 19th Infantry and the separate 503rd Parachute Regimental Combat Team of Lieutenant Colonel George M. Jones to spearhead the assault. The main threat to the amphibious assault vessels and supporting warships was land-based Japanese kamikaze aircraft, whose use the Japanese had begun as a desperate measure during the final stages of the 'Battle of Leyte' and extended by December 1944.
Early in December, USAAF and US Navy aircraft attacked Japanese air bases to destroy potential kamikaze aircraft before they could attack, and US airmen claimed the destruction of more than 700 aircraft on the ground.
On 13 December 1944, two days before the scheduled assault on Mindoro, kamikaze aircraft attacked the US Navy task force delivering the landing force. The light cruiser Nashville was hit by a kamikaze, losing more than 130 men killed and having another 190 men wounded. Brigadier General William C. Dunkel, the commander of the Western Visayan Task Force landing team, was among the injured. Other kamikaze attacks damaged two tank landing ships and disabled several other ships.
The US landing on Mindoro began on 15 December, when the prevailing clear weather allowed the full exploitation of US air and naval power, the latter including six escort carriers, three battleships, six cruisers and many other support warships against light Japanese resistance. Because of inadequate airstrip facilities in Leyte, the 503rd Parachute Regimental Combat Team, on the left of the Western Visayan Task Force, came ashore in Mangarin Bay, to the north of San Jose, with the 19th Regimental Combat Team landing force on the right. Destroyers provided fire support for the troop landings and anti-aircraft protection for the ships in the transport area.
Two LSTs struck by kamikaze aircraft were abandoned and sank. The destroyer Moale, commanded by Commander Walter M. Foster, went alongside the burning LST-738, which was loaded with aviation fuel and ordnance, to rescue its crew. Several explosions aboard the landing ship caused damage to Moale as she pulled away. Some fragments were 2 ft (0.61 m) square, and their impacts put four holes in Moale's hull. Moale suffered one man killed and 13 wounded, but rescued 88 survivors.
There were 1,000 defending Japanese soldiers of Lieutenant General Shizuo Yokoyama’s 8th Division on Mindoro, and these troops were supplemented by 200 survivors from ships sunk off Mindoro en route to Leyte. The defenders were outnumbered and outgunned. After securing their beach-head round San Jose, the US forces advanced to th north. The 502rd Parachute Regimental Combat Team detached one battalion to make another landing on the islands’s north-west coast, while the 19th Regimental Combat team complemented its advance along the eastern coast with three battalion-strength landings on this same coast. Some 300 Japanese manning an air raid warning station at the island’s northern end put up a stiff fight against a company of the 503rd Parachute Regimental Combat Team, but except for mopping-up operations completed on 24 January 1945, the island had been secured within 48 hours.
The Japanese forces defending Mindoro suffered some 200 men killed and 375 wounded, and she survivors fled inland into the island’s jungles, where they lurked until the end of the war. The 24th Division lost 18 men killed and 81 wounded.
By the end of the first day, US Army engineers were at work preparing airfields, and two such facilities were completed in 13 days. These airfields allowed US aircraft to provide direct support for the invasion of Luzon. The Mindoro airfields were also used by long-range aircraft, especially USAAF Consolidated B-24 Liberator four-engined heavy boimbers, to attack Japanese shipping in the area between Luzon and Formosa. The bombers also operated over the South China Sea, and combined with ships and aircraft of the US Navy to blockade shipping between Japan and South-East Asia.
A brigade-sized Penetration Unit, carried in one heavy cruiser, one light cruiser and five destroyers, departed Cam Ranh Bay in Japanense-Occupied French Indo-China on 24 December to land on Mindoro, but after nearing the western coast of Mindoro realised the impossibility of the situation of the last Japanese on the island, where the US force were mopping-up the last pockets of resistance, and turned back to Cam Ranh Bay.