Everyone coming from the mainland - including Hong Kong residents - will be put into compulsory 14-day quarantine from Saturday midnight as desperate Chief Executive Carrie Lam Cheng Yuet-ngor tries to stop a growing community spread of the Wuhan coronavirus.
Lam has been facing intense pressure in recent weeks to significantly control the number of arrivals from the mainland, with hospital staff going on strike for a third day yesterday to demand a total border shutdown.
In a de-facto lockdown of the border, Lam invoked the Prevention and Control of Disease Ordinance to impose compulsory quarantine on those arriving from China, where the epidemic continued to spike to 24,430 patients yesterday, with 493 deaths - 68 more than on Tuesday.
Two fatalities have been recorded outside the mainland - in Hong Kong and the Philippines. The United States, Australia, Singapore, the Philippines and a growing number of countries are denying entry to foreigners traveling from China to limit the spread of the deadly coronavirus.
"This is the second time that we are invoking this ordinance,' Lam said. "On January 8, we included the novel coronavirus as a reportable disease. We already put in place relevant legislative measures early on."
But the quarantine measure will not take effect until Saturday midnight as "details of subsidiary legislation and quarantine arrangements" are pending and will be announced later.
Despite not completely banning anyone from arriving in the SAR from the mainland, Lam said the compulsory quarantine would deter people - Hong Kong citizens, mainlanders and foreigners - from crossing the border unless strictly necessary.
"If it's not absolutely necessary or for emergency purposes, I believe mainlanders won't come to Hong Kong and Hongkongers won't leave the city easily," she said.
Hong Kong citizens will be put under home quarantine but isolation arrangements on non-local residents are yet to be laid out. Lam said details will be announced later.
Secretary for Food and Health Sophia Chan Siu-chee said the policy covers anyone who enters the SAR from the mainland.
Those who come from non-mainland cities but have been to the mainland in the past 14 days will also be put under mandatory isolation.
Asked if the current quarantine centers in holiday camps will be sufficient to isolate all non-SAR residents, Chan said arrangements will be announced after the government has finished drafting the law.
Infectious disease expert Ho Pak-leung from the University of Hong Kong said Lam's announcement is equivalent to a complete closure of borders.
But he criticized the three-day delay in implementing the new measure. "It is unacceptable that anyone coming to Hong Kong from the mainland in these few days can still walk around in the community," he said.
"The virus will not wait. I hope all policies can take effect as early as possible. If there is a transitional period, something should be done in the meantime."
Lam on Monday closed four additional mainland-Hong Kong control points but left Shenzhen Bay open, as well as the airport and the mega bridge to Macau and Zhuhai, which took effect at midnight on Tuesday.
Arrivals of visitors and Hongkongers from all border points on Tuesday dropped 46 percent or 61,192 people since then.
Mainland visitor arrivals went down 29 percent to 9,511.
But Lam said some 28,000 people still came back from the mainland - of whom about 80 percent were Hong Kong citizens - which still posed a risk of bringing the coronavirus to the city.
She said Hong Kong saw six more cases in the past two days, taking the total to 21, with some patients having no travel history, indicating community spread.
"The coming two weeks is a key period. We need to prevent the disease from spreading by taking more stringent measures as suggested by four experts in a meeting with me yesterday," she said.
Also to compress traveler flow to Hong Kong, Lam said Cathay Pacific and Cathay Dragon will cut 90 percent of mainland flights and only keep flights between Hong Kong and four mainland cities, including two daily flights to Beijing, two daily to Shanghai, one daily to Xiamen and four in a week to Chengdu.
Lam called for citizens to stay at home and prevent going to crowded places, as she said "social distancing" could lower the risks of transmission.
HKU's Ho also called on the government to set heavy penalties against those who hide their mainland travel history or violate the quarantine order as a deterrent effect.