Eight healthcare workers at Melbourne's Alfred Hospital have tested positive to COVID-19.
Alfred Health confirmed on Sunday five of the cases are not linked and are believed to have been acquired through the community.
Three colleagues deemed close contacts also tested positive.
Alfred Health chief executive Andrew Way says the hospital is taking "every measure" to keep staff members safe.
"We cannot afford to become complacent," Professor Way said.
This week, hospital administrators began requiring all visitors and staff in clinical areas to wear surgical masks and increased the frequency of cleaning in its infectious diseases ward, where COVID-19 patients are treated.
They have also placed a concierge at the entrance to the ward to ensure the movements of all staff are logged. The general public and visitors do not have access to the high-risk ward.
It comes after three cancer patients died in March after contracting COVID-19 at the hospital.
Victoria recorded its seventh straight day of triple-digit increases on Sunday with 273 new cases.
A man in his 70s died on Saturday night while another man in his 90s died on Friday night.
The state's virus death toll is 24, bringing the national toll to 108.
Chief Health Officer Brett Sutton said he was hopeful cases numbers would plateau within three to five days given stage three restrictions in Melbourne and Mitchell Shire had curbed public movement.
Known outbreaks include 138 cases linked to the North Melbourne and Flemington public housing towers, which have a degree of crossover with 134 cases linked to Al-Taqwa College.
Ten cases are linked to Menarock Aged Care in Essendon, seven are linked to Glendale Aged Care Facility in Werribee and seven to the Catch.com distribution centre in Truganina.
Smaller clusters of five or less have been identified at Cenvic Construction Riverina Apartments in Footscray, Debney Meadows Primary School, Somerville Meats Retail Services in Tottenham, PM Fresh facility in Broadmeadows and Ilim College.
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