Complex sentence: The Japanese put up stiff resistance around the high ground at Katika, but were eventually forced back and by the end of the Australians, having suffered 94 casualties in the process, secured a beachhead several kilometres deep.
Split into simpler sentences: The Japanese put up stiff resistance around the high ground at Katika, but were eventually forced back. By the end of the day, having suffered 94 casualties, the Australians had secured a beachhead several kilometres deep.