Health, police and fire services staff are among the 533 infected cases, the government said on Wednesday night as it urged residents to test daily for the virus using Rapid Antigen kits.

The Chinese special administrative region carried out three city-wide mass coronavirus tests for its more than 600,000 residents in the space of a week. More than 7,000 people are in mandatory quarantine.

Sands China's (1928.HK) Sheraton hotel located on Macau's Las Vegas style Cotai strip has allocated 2,000 rooms to asymptomatic patients.

More than 20 zones across the city are locked down as authorities try to cut the chains of transmission for the rapidly spreading BA.5.1 Omicron variant.

Authorities have asked people to remain at home as much as possible with most of the city effectively closed, including bars, hair salons and outdoor parks. Only takeaway is allowed from dining facilities.

Casinos, while mostly deserted, are allowed to stay open, the city's government said, in a move to protect local jobs.

The stringent measures come after Macau has been largely COVID-free since an outbreak in October 2021.

Macau adheres to China's "zero COVID" policy which aims to eradicate all outbreaks, at just about any cost, running counter to a global trend of trying to co-exist with the virus.

Macau's cases are still far below daily infections in other places, including neighbouring Hong Kong where cases have jumped to close to 2,000 a day this month.

Macau only has one public hospital with its services already stretched on a daily basis. The territory has an open border with mainland China, with many residents living and working in the adjoining city of Zhuhai.