 After organizing his force while waiting for the 1st Battalion, 141st Infantry Regiment, Komori began his advance on Arawe on 24 December. He arrived at the airstrip to the north of Arawe during the early hours of Christmas Day. During that morning, elements of the Komori Force ambushed two platoon-sized American patrols traveling in trucks northeast of Umtingalu. The American units withdrew to the village and reinforced "G" Troop's defensive position there. The American force defeated several Japanese attempts to move around Umtingalu during the day, and killed at least three enemy soldiers. Cunningham believed that the force encountered around Umtingalu was the advance guard of a much larger body of Japanese soldiers advancing from Gasmata, and withdrew the troopers stationed around the village to positions behind the MLR. At 10: 30 pm that night, 50 Japanese soldiers made a poorly coordinated attack on the MLR. While they succeeded in overrunning some American positions, the Japanese were repulsed by fire from the 112th Cavalry's 60-millimetre (2.4 in) mortars. The Americans lost one man killed and eight wounded, and estimated that the Japanese had suffered twelve casualties.
