Hong Kong's leader said Sunday that coronavirus was spreading out of control in the city as she announced a record daily high of more than 100 cases and ordered new social distancing measures.
The finance hub was one of the first places to be struck by the virus when it emerged from central China.
But the city had impressive success in tackling the disease, all but ending local transmissions by late June.
However, in the last two weeks, cases have begun to spike once more and doctors fear it is spreading undetected in the densely packed territory of 7.5 million people.
On Sunday, chief executive Carrie Lam said more than 500 infections had been confirmed in the last fortnight, bringing the city's total tally to 1,788 cases with 12 fatalities.
More than 100 were confirmed on Sunday alone, a record daily high for the finance hub.
"I think the situation is really critical and there is no sign the situation is being brought under control," chief executive Carrie Lam told reporters.
Lam announced new social distancing measures last week, shuttering many businesses including bars, gyms and nightclubs, and ordering everyone to wear masks on public transport.
Restaurants were ordered to only offer takeout services in the evenings.
On Sunday, Lam announced new measures including plans to make it compulsory to wear masks inside any public indoor venue -- and a new order for non-essential civil servants to work for home.
As hospital wards fill up, officials are also scrambling to build a further 2,000 isolation rooms on barren land near the city's Disneyland resort to monitor and treat those who test positive, she added.
Hong Kong was already mired in recession when the pandemic hit thanks to the US-China trade war and months of political unrest last year.
The new partial lockdown has compounded the economic misery.
On Sunday, Lam called for landlords to look at lowering rents.
She said further social distancing measures would be rolled out if the daily infection rate did not ease in coming days.