One of the two police officers assaulted in a Waikato baseball bat attack suffered a skull fracture and remains in hospital.
The two police officers were assaulted in Hamilton overnight following a routine traffic stop.
A vehicle containing three people in Fairfield just after midnight was stopped and the officers were speaking to the driver when he allegedly produced a baseball bat and attacked them.
Both police officers were taken to Waikato Hospital.
One officer suffered a concussion and was discharged, the other suffered a skull fracture and remains in hospital in a stable condition, a police spokesperson said.
A 17-year-old male was arrested and will appear in the Youth Court.
The spokesperson said the two officers involved would like to express their gratitude to well-wishers and asked for privacy.
Police Association president Chris Cahill said the seriousness and violent nature of offences against police are becoming more common.
"More people are willing to attack police with weapons or inflict injuries upon them and that shouldn't be acceptable by anyone," he told the Herald.
"In this case it's a concern a 17-year-old could use such violence against two officers and clearly unprovoked and it adds a level of concern around this assault given the offender's age."
Cahill calls for the Youth Court to hand down a serious sentence to the offender to send a clear message that violent attacks on officers "will not be tolerated".
"This isn't a bit of minor youth offending, this could have resulted in the death of an officer and certainly permanent injury and it needs to be treated at that level of seriousness," he said.
Cahill said if there aren't consequences for serious offence it emboldens offenders.
The two officers injured in this attack will also face long-term psychological effects, as well as their families, he said.
Cahill said he worries daily for the safety of officers.
"It's become more dangerous without a doubt and a lot of it is that people are willing to make more serious assaults on officers, whether it be firearms or baseball bats ... I worry every day."