From 6 January onwards, Ambon was attacked by Japanese aircraft.
Allied aircraft made some sorties 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 fighters. 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 The remaining Allied aircraft were withdrawn that day, although RAAF ground staff remained. Within a day of the Japanese landings, the Dutch detachments in their vicinity were overrun and/or had withdrawn towards Paso.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 its 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.