The Japanese aircraft, which I believe were Kawanisi 'Mavis' flying boats, flew singly in wide circles, dropping the occasional bomb at random. The loud droning of their engines kept us awake and out of bed for long periods. I cannot recall any anti-aircraft fire or searchlights. There were no RAAF or USAF fighters in Port Moresby at that time.
Flight Lieutenant William J. Gibbs, RAAF Meteorological Service. Read his account.
The first Japanese air raid occurred on 3 February, 1942. Between 3:00 am and 3:30 am, six Japanese flying boats bombed Port Moresby. The air raids continued throughout February and March. They began to seriously affect Australian troops' morale.
Eventually the Japanese flying boats departed and we returned to our beds and a somewhat fitful sleep. The Japanese flying boats paid another visit an the night of 5 February with a similar routine, the primary objective of which appeared to be to deprive us of sleep. – Flight Lieutenant William J. Gibbs, RAAF Meteorological Service
On 15 February, the Australian Territories of Papua and New Guinea were put under military rule. They were now overseen by the Australian New Guinea Administrative Unit (ANGAU). Major General Basil Morris was the commanding officer.
The Japanese would go on to conduct over 100 bombing raids against Port Moresby. These were aimed at strategic facilities such as airfields and gun batteries, as well as at the township.
During February and most of March, there were no Allied aircraft in Port Moresby. The only defence was ground-based Australian Army anti-aircraft batteries and machine guns. On 21 March, Kittyhawk fighters from No. 75 Squadron RAAF arrived. Ten days later, the United States Army Air Force joined the RAAF in fighting the Japanese.