The Japanese put considerable stress on night operations. At night they use much closer formations than during the day in order to prevent loss of contact. Often they dig individual slit trenches for use during the night, with sentries usually posted within a radius of 50 to 150 yards of the bivouac. To surprise and confuse the opposition is one of the major night objectives, and this result is gained by silent infiltrations around the flanks and between defense areas. Frequently the Japanese crawl great distances at night to a point where they can leap upon the opposing forces before the latter are able to take action.
26. CONDUCT OF THE ATTACK
Preparatory to some night attacks, small patrols were sent out during the day to locate the approximate positions of the opposition, particularly those of heavy weapons. In Dutch Borneo, for example, the Japanese exposed men during the daytime to draw the fire of Dutch machine guns so that their positions could be determined for the night attack. After getting information on these positions, the Japanese sent out additional small patrols early at night to determine more exactly the Dutch defensive locations.
After the patrols returned, the night attack began. Strong patrols, preceded by small guide groups which cut and rolled back barbed wire and removed other obstacles, advanced in extended order toward the opposition. Meanwhile, the Japanese hit on hard objects with bamboo sticks and made vocal noises in imitation of machine-gun fire in order to draw the fire of the Dutch so that their positions could be ascertained definitely. At the same time, the deceptive noises caused native troops to become panicky—a result which the Japanese probably expected.
Once having located the defending machine-gun positions, some of the Japanese crawled silently to the locations and disabled the crews with knives and hand grenades. One Dutch stronghold of 25 men was overcome without a shot being fired. Other Japanese, meanwhile, crept up to rifle troops and disarmed them with jiu jitsu tricks. Some of the defenders were able to escape by kicking away the hands that clutched them. Many casualties resulted from oral orders given by Dutch officers, for the Japanese, trained in the Dutch language, overheard the orders and shot the officers. In several instances some of the Japanese spoke out in Dutch and asked for the commander who, upon answering, was shot. When the Japanese had neutralized the Dutch outer defenses, they sought to penetrate further with strong patrols.
After some of these initial night fights in Borneo they withdrew 500 to 1,200 yards, and Japanese naval guns bombarded the defending positions the next day while the infantry, except for normal patrol duties, stayed inactive.
Many of the Japanese had copies of all the Dutch secret maps, and before landing they apparently had planned their attacks thoroughly.