The Mandurah Basketball Association president says there will be "swift, strong actions" against members found to have been involved in a brawl during a match last week.
Police said 15 vehicles attended the incident at 6.40pm on November 5, which involved about 60 people including adults and children, at an under-13 girls basketball match at the Mandurah Recreation Centre.
A 58-year-old male referee who tried to break up the argument was bitten on his forearm and taken to Peel Health Campus, before being discharged later that evening.
A 35-year-old Mandurah woman has been charged with taking part in a riot and a 71-year-old Coodanup woman has been charged with aggravated common assault and riotous behavior.
They are due to appear in the Mandurah Magistrates Court on November 29.
A 15-year-old Mandurah girl has been charged with aggravated assault occasioning bodily harm and taking part in a riot. She is due to appear before the Mandurah Children's Court on December 2.
Mandurah Basketball Association president James Waldeck said the behaviour was "unacceptable" and would not be tolerated.
"There will be swift strong actions against any members who are found to be involved in the instigation of this incident," he said.
"We want to take this opportunity to assure our members that this incident was a community matter and was not basketball related, despite it having occurred while a game was in progress.
"Mandurah Basketball Association are working closely with the Police and the City of Mandurah in our management of this situation.
"We value our people and are extending support services to any of our members who may have been affected by this. We wish to assure you all it's business as usual at Mandurah Basketball."
The investigation is ongoing and police would like to speak to anyone who saw the incidents and anyone with information is urged to call Crime Stoppers on 1800 333 000 or report online at www.crimestopperswa.com.au.