Late in the battle, on March 25th, when it seemed things were mostly stabilized, a group of approximately 300 of the Japanese attacked the Army Air Corps camp at the airfield. An ad-hoc group of Army, Navy, Marines, and
The Marines had gone around the island as they took control and rather than enter the caves, had just blasted the entrances shut. They didn't know exactly how many Japanese. were still alive, but at the end of active hostilities, there were over 3,000 Japanese troops still alive on the island. Some certainly committed suicide, but over the months and years following, 867 more Japanese surrendered and 1,602 were killed. The last 2 known Japanese survivors surrendered in 1951.
*UPDATED to reflect the correct organizational title of the Seabees, from a comment by KurtP who blogs at A Trainwreck in Maxwell