Tasmania has declared eight Melbourne premises high risk and told anyone who has recently been to the locations to isolate immediately.
The directive comes after it was revealed on Wednesday night a quarantine worker in Melbourne tested positive to COVID-19.
The eight venues are in the suburbs of Noble Park, Keysborough, Brighton, Brandon Park, Springvale and Heatherton.
Authorities have ordered anyone who was at the venues from January 30 to February 1 to self-isolate and contact the public health hotline.
People who've been at the high-risk locations across those dates need to apply for special permission if they want to enter Tasmania.
Tasmania also has border restrictions in place with three Western Australian regions, Perth, Peel and the South West, but is open to the rest of the country.