Police are discouraging people from taking the law into their own hands following a brawl outside a liquor store in Otara.
The fight on Franich Street began at 5.30pm on Tuesday when a teenager entered the store and was turned away because he was underage.
He is said to have returned with four friends who attempted to rob the store of alcohol.
The shop owner confronted them and several weapons including a knife were used in the ensuing fight. Four people were taken to hospital.
It is believed the shop owner used a hockey stick against the youths - something that Detective Senior Sergeant Dave Pizzini does not endorse.
He is not ruling out charging the shop owner in connection with the incident, saying police are investigating the criminal liability of everyone involved.
Charges against four youths are expected to be laid on Thursday.