The city announced 607 locally transmitted cases on Monday and cases have soared since January with more than 2,000 infections in total, compared with just two in December.
Health Secretary Sophia Chan said on the weekend that she expects cases to continue to rise “exponentially”.
Hong Kong has become one of the world’s most isolated places because of its travel restrictions and intermittent lockdowns that have accelerated a brain drain from the former British colony.
The city, along with mainland China, is one of the few places in the world still pursuing a zero-Covid strategy.
While other countries have opted for vaccination as a route out of the pandemic, the strategy seeks to eliminate all Covid transmission.
Restaurants are under strict orders to close at 6pm local time and most people continue to work from home.
In total, Hong Kong has recorded 213 Covid-related deaths and around 15,000 cases since early 2020.
Around 80 per cent of the city’s 7.5 million residents have had one Covid-19 jab.
But government figures show that most elderly people remain unvaccinated.