A teenage girl was knocked unconscious and glass bottles were thrown at police after brawls erupted at a Blackalls Park party.
Officers from Lake Macquarie Police District attended Rhodes Street about 10pm on Saturday after reports a large house party was out of control and spilling onto the street.
There were more than 150 people on the street when police arrived and some threw glass bottles and other items at the officers and their vehicles.
Additional police attended after numerous people started fighting, which resulted in a girl, 17, being knocked unconscious.
She was later taken by NSW Ambulance paramedics to John Hunter Hospital, where she remained on Sunday morning in a stable condition.
The group continued to brawl and police used pepper spray in an attempt to disperse the crowd.
Officers from Newcastle City Police District, the Dog Unit and Operations Support Group also attended to assist and move the large group along.
Lake Macquarie Police District Acting Inspector Paul Battley said about 30 police attended the scene.
He said police believed a 16 year old boy whose parents were away for the weekend decided to hold the party without adult supervision and it spiralled.
"[It was] just juveniles who were alcohol affected and didn't like to be told they their party was going to be shut down by police due to the excessive noise and the disruption to their neighbourhood," he said.
Witness Brock Meredith said he attended the scene to try and find his brother, who had been at the party.
His dashcam recorded brawling members of the crowd rush onto the road and several people falling over.
"It seems we got there right in the middle of it all starting and we were surrounded by a large group of people and a fight broke out right in front of the car," he said.
"We saw bottles getting chucked at police and their vehicles.
"Was all very scary.
"We were stuck there for a few minutes.
"Eventually my brother found us and he came to the car and yelled at everyone to get out of the way, there was a few groups of kids chucking bottles at the cops and the cop cars but bottles were flying from everywhere.
"We were right near them but lucky we didn't get any damage at all."
Five people were arrested and will be charged with offences including hindering police, resisting arrest, offensive behaviour, possessing prohibited drug, possessing knife and trespassing.
Acting Inspector Battley said two men aged 23 and 19 received court attendance notices.
Police will allege a Teralba man, 23, physically interfered while a Sergeant was dealing with another man, and violently resisted other police who came to assist.
A police dog also assisted with restraining the man, who received hospital treatment for a dog bite to his left calf.
Acting Inspector Battley said one of the people charged was in possession of a knife.
"He didn't use it against any police officers, but after he was arrested he was found to have a knife in his possession," he said.
"It's very concerning."
He said police would be speaking in coming days to several other young people aged 15 to 17 "who may or may not be dealt with under the Young Offenders Act".
Investigations into the incident, including the assault of the girl, are continuing.
Police have asked anyone with information to contact Crime Stoppers.