Complex sentence: A follow up landing was made by the 37th/52nd Infantry Battalion on Karkar Island, while the 35th Infantry Battalion secured a large quantity of abandoned Japanese stores at Hansa Bay, and pushed patrols towards the Sepik River.
Split into simpler sentences: A follow up landing was made by the 37th/52nd Infantry Battalion on Karkar Island. Meanwhile, the 35th Infantry Battalion secured a large quantity of abandoned Japanese stores at Hansa Bay, and pushed patrols towards the Sepik River.