sentences:  Those constant and well organized attacks, along with intelligence provided by documents captured by AIB patrols at the end of May, indicated that the Japanese 18th Army, using 20th and 41st Divisions based at Wewak and its surroundings, were preparing something much bigger.Having broken Japanese codes earlier in the war, they found out that Adachi planned to retake Tadji Airfield, in order to delay the American forces push toward Western New Guinea and the Philippines.During June, American forces started reinforcing their position at Anamo and Afua along the Driniumor River, with some patrols venturing eastward of the river to keep contact with the Japanese.