A dozen crew members from a ship that docked in Fremantle have tested positive for COVID-19.
Three crew members of the Stolt Sakura have been transferred to hospital.
Two patients are being treated in intensive care – one is in a serious condition.
Premier Mark McGowan says he expects all other crew members will remain on the ship in isolation- unless medical attention is required.
The cluster comes as an Australian diplomat who arrived from Serbia also tested positive for the virus after being directed to self-quarantine with his family.
The Premier maintains the risk to the community is low – but is calling for more Western Australians to get vaccinated.