A 13-year-old boy has been arrested after hitting another teenager in the head with a hammer in Levin.
Senior Sergeant Sarn Paroli said the attack happened about 10pm yesterday.
The boy was initially arrested but had since been dealt with by police youth aid, Mr Paroli said.
A 17-year-old man suffered head injuries but did not require hospitalisation.
The teenagers knew each other, Mr Paroli said.