Police patrol a party district making sure bars are abiding by COVID-19 coronavirus restrictions in Hong Kong on Dec 24, 2020. (ISAAC LAWRENCE / AFP)

HONG KONG - Hong Kong extended a compulsory quarantine by an extra seven days to 21 days for all visitors outside the Chinese mainland, effective Friday, in stepped-up efforts to prevent a new variant of the novel coronavirus from spreading on a day the city saw 57 fresh cases.

Authorities also banned all people who have stayed in South Africa in the past 21 days from boarding for Hong Kong

Authorities also banned all people who have stayed in South Africa in the past 21 days from boarding for Hong Kong.

READ MORE: HK sees 71 new virus cases as experts monitor S. African strain
Hong Kong has already banned all flights arriving from the United Kingdom from Monday and the city said on Wednesday two students who returned from the UK were likely to be infected with the new super-virulent strain of COVID-19.

In a statement issued shortly after midnight Friday, authorities said people who have stayed in places outside the Chinese mainland during the 21 days before their arrival have to undergo 21 days of compulsory quarantine in designated quarantine hotels.

"Noting the drastic change of the global pandemic situation with the new virus variant found in more countries, there is a need for the government to introduce resolute measures immediately... to ensure that no case would slip through the net even under very exceptional cases where the incubation period of the virus is longer than 14 days," a government spokesman is quoted as saying in the press release. 

ALSO READ: HK secures 22.5m doses of vaccines, enough for all citizens

Apart from the requirement to be tested at community testing centres or designated quarantine hotels on the nineteenth or twentieth day following their arrival in Hong Kong, those arriving will have to stay "at their place of residence, private premises or the place of quarantine specified on the quarantine order" until the test result is available.

Also on Friday, the Centre for Health Protection of the Department of Health announced that with 57 additional confirmed cases of COVID-19 being investigated, the number of cases in Hong Kong so far stood at 8,482, including one probable case.

Among the newly reported cases, two patients had a travel history during the incubation period.

A total of 1 133 cases have been recorded between December 11 and 24, including 1,047 local cases of which the origin of 400 couldn't be ascertained.

Separately, two people were arrested as the Food and Environmental Hygiene Department (FEHD) stepped up inspections and conducted joint operations with police and other departments to enforce anti-epidemic regulations across the territory over the Christmas holidays. On Dec 24, FEHD alone inspected 108 catering premises and 4 other premises were inspected during the joint operations, and 593 catering premises and 13 other premises. 

As at 9 am on Dec 25, 114 COVID-19 confirmed patients were discharged from hospitals in the past 24 hours, according to a Hospital Authority press release. So far, 7,317 patients with confirmed or probable infection have been discharged across the city.

With inputs from Agencies