The battle of Noemfoor (2 July-30 August 1944) was a US amphibious landing carried out in order to make up for slow progress on Biak and the resulting shortage of airfields in western New Guinea.
Biak had been attacked on 27 May, and the aim was to capture its three airfields and use them to support Nimitz's attack on the Caroline Islands. It soon became clear that Biak was a much tougher target than had been expected, and its airfields wouldn't be available in time. In order to compensate this MacArthur decided to attack Noemfoor, sixty miles to the west of Biak.
Noemfoor contained three airfields, including one 5,300 foot long strip, and was defended by around 3,000 men under Colonel Suesada Shimizu. The garrison was made up of around 2,000 men from the 35th Division, and 1,000 Formosan and Javanese workers. It was used as a barge staging post for troops moving to reinforce the garrison of Biak. The island was largely circular, with a similar difficult coral terrain to Biak.
The attack was to be carried out by the 158th Regimental Combat Team (General Edwin Patrick), reinforced to bring it up to a strength of 8,000 men. Planning for the attack began on 4 June, and involved moving a replacement unit from the 6th Division to Wakde to relieve the 158th.
D-Day for the attack was set for 2 July 1944. It was preceded by a naval bombardment conducted by HMAS Australia, two US light cruisers and fourteen destroyers. The air bombardment began before D-Day. On 1 July a massive strike was carried out, involving 84 B-24s, 36 A-20s, 12 B-25s and 22 P-38s. On 2 July 33 B-24s, 6 B-25s and 15 A-20s attacked the island.
The air attack ended 10 minutes before the landings, and the first wave of American troops found the Japanese defenders of the beach area still stunned by the attack. The only delays were caused by the tendency of the lead units to stop to mop up pockets of resistance which should have been left to follow-up units.
On 3 July the Americans sent out patrols in an attempt to find the main Japanese positions. A few potentially strong defensive positions were found but they were unmanned.
The Americans took a number of prisoners during the initial assault. Interrogation of one of the prisoners suggested that there were 5,000 Japanese troops on the island, and so MacArthur decided to send reinforcements, 1,400 men from the 503rd Parachute Infantry Regiment. The first contingent would drop on 3 July, with the second and third battalions following on the next two days. Their target was the main airfield at Kamiri, but the drop was carried out at too low level and over too wide a strip of land, causing some 140 casualties, about a third of them serious. The second jump went better, although the hard coral still caused some problems. The third jump was cancelled.
The Japanese mounted a major counterattack early on 6 July, hitting an American position on Hill 201, near one of the Japanese garden areas. The attack was repulsed and the Japanese lost around 200 dead. Despite this counterattack, which was the last organised Japanese resistance, all three airfields had been secured by 6 July and the better two were in use by the end of the month. This allowed them to be used in the next attack, the invasion of Sansapor on the Vogelkop Peninsula at the western tip of New Guinea.
Mopping up operations were frustrating, with contact with the Japanese often lost for several days, but they were largely over by 31 August. During the invasion the Americans lost 70 dead, the Japanese around 1,900, most of the fighting strength of the garrison.