Police are investigating a report of a teacher at Kailua High School hitting a boy with a hammer yesterday.

The teenager and his parents reported the incident yesterday after the boy received four stitches, police said.

A second-degree assault case was opened, but when officers went to the school, the teacher was no longer there. 

Police said a hammer was thrown at the boy, who was hit in the head.

The Department of Education issued a statement, saying the matter is under investigation, and the teacher is on leave pending the results.