On 12 April 1942, a Japanese convoy steamed into Dore Bay and began landing approximately 4,000 men. The area was already well known to the Japanese, as the area was the location of a cotton plantation developed by the government-sponsored "Nan’yō Kōhatsu" development company from the early 1930s. At the beginning of 1942, the Royal Netherlands East Indies Army (KNIL) garrison at Manokwari consisted of approximately 125 KNIL troops, which included a number of civilians reservists and home guard who had been called up at the start of February 1942. As the KNIL ground force had no chance of successfully engaging the Japanese invasion force, it withdrew into the interior of Dutch New Guinea and initiated guerilla warfare.