Although the Japanese had been blasted out of Yigo, they had enough strength remaining to trouble the US 77th Infantry Division. Encouraged by a recent armored night raid, which had wreaked havoc in the lines of the 305th Infantry Regiment, the Japanese decided to put the 306th to the same test. Late in the evening, several enemy infantry patrols felt out the American positions. At 02:00 tanks were heard approaching from the north. The Americans readied bazookas and flame-throwers, the only anti-tank weapons available in the moonlit night.