A man was stabbed and bottles were thrown at an ambulance - endangering its crew - when a 21st birthday party turned into a drunken street brawl in Lower Hutt.
The man, said to be in his late teens or early 20s, is in a serious condition in hospital with six stab wounds.
Police said they were called to Waddington Drive, in the suburb of Naenae, about 2.30am, after reports of a fight that involved up to 50 people.
They arrested a man for assault, while eight others were arrested for disorder and obstruction.
The ambulance which attended the scene to pick up and treat the injured man was pelted with bottles, and they narrowly missed its crew.
The Wellington Free Ambulance said paramedics arrived to an "unruly, intoxicated scene".
Ambulance Association president Mark Quin said such incidents were becoming more and more commonplace.
"Particularly on those Thursday, Friday and Saturday nights in metropolitan areas it's becoming almost an expectation to staff that they will walk into or be involved in some sort of incident where they are either verbally abused or worst case scenario, physically abused."
Mr Quin said attacks on staff were almost always fuelled by alcohol or drugs.
"Unfortunately there are sections of our society who don't respect [us] and due to whether it's alcohol, or drugs, they do not respect the uniform or the people in that uniform."
He said there were policies and training in place for staff when it came to dealing with verbal or physical attacks, or dangerous situations.
However, it was also about educating the public that such behaviour was not okay, he said.
Mr Quin said the problem could get worse.
"We've been lucky across New Zealand, while we have had staff assaulted we haven't had a death or a major injury, but one's got to wonder how far away that will be unfortunately."