Mandurah Detectives have charged four more people after a brawl with more than 30 juveniles, including school children, occurred at a Secret Harbour shopping centre on Tuesday.
Police are investigating the fight which happened about 4pm on Tuesday, outside the Woolworths shopping centre in the Secret Harbour Square.
Three people were injured and treated at the Peel Health Campus.
A 24-year-old man from Warnbro has been charged with Taking Part in a Riot and Obstructing Public Officers.
A 19-year-old Port Kennedy man and an 18-year-old Warnbro man have each been charged with taking part in a riot.
A 16-year-old boy has been charged with taking part in a riot, and damage.
A 16-year-old boy, and 15-year-old girl are also currently assisting police with their inquiries.
A Warnbro man was charged on Wednesday with assaulting a public officer, obstructing public officers and taking part in a riot.
A 14-year-old Secret Harbour boy will be referred to the juvenile justice team.
Detectives are urging anyone who saw the fight, or has vision of the incident to come forward and contact them.
Anyone with any information is asked to call Crime Stoppers on 1800 333 000 or report online at www.crimestopperswa.com.au.
People providing information to Crime Stoppers may remain anonymous if they wish.