POLICE have called for a community meeting in response to the fights at a party held at Schofields community hall on Saturday.
A Quakers Hill police spokesman said they would invite the party organiser, Blacktown Council (which rented out the facility at Railway Terrace), parents and community groups.
The incident got big public response after a parent reported it on Facebook.
The spokesman said police detained several people after about 30 police officers from Blacktown, Mount Druitt, Quakers Hill (including dog and riot squads) sped to the scene at 9.45pm.
He said the suspects were aged 15 to 20 and were arrested for assaults, on drugs and alcohol charges and for being public nuisances.
The spokesman said no one was seriously injured.
A parent who took her daughter, 16, and her girlfriend to the party said she contacted Riverstone police station enquiring if a party had been registered.
"The constable said no party had been registered and asked me to contact Quakers Hill police who also said they weren't aware of it," she said.
"I told Quakers Hill police the party had been posted on Facebook and I was concerned it could get out of control and the officer said he would send a patrol car around.
"I later asked one of the organisers who was responsible for security and I was told entry was by invitation only. On hearing this I became uncomfortable and told my daughter and her friend I would stay outside in my car and that they had to be out by 10pm.
"Within the hour more people were arriving carrying cases of beer and bottles of spirits."
About 9.40pm the first of the fights started outside the hall and spilled onto the road.
"I saw a boy being bashed by five other boys and one of them pulled a knife.
"I also saw a boy pulling a gun out of his pocket."
Were you at the party?
How do you think security at young people's parties can be improved? Tell us at: blacktown sun.com.au.

