(To watch the full press briefing with sign language interpretation, click here.)

The Centre for Health Protection today said it is probing 14 additional COVID-19 cases, of which nine are imported, four are epidemiologically linked with imported cases, and one is possibly import-related.

All of the cases involve mutant strains.

The linked cases include an 83-year-old woman who is a household contact of a previous case, and a man aged 20 who had a dinner at the Nabe Urawa restaurant at Hysan Place in Causeway Bay on January 4.

The centre's Communicable Disease Branch Head Dr Chuang Shuk-kwan also reported at a press briefing this afternoon that less than 10 preliminary positive cases have been detected, including two nurses who work in the same clinic in Tuen Mun.

She said: "They work in the same clinic, but they did not have an overlap of their work schedule in the recent few days.

"One of the nurses is a part-time nurse who accompanied the doctor to see one of the cases confirmed earlier on January 3. So we consider that incident may be the likely source of infection for that nurse.

"As for how come the second nurse got infected? It is possible that there was some silent transmission in the clinic setting among the staff of that clinic."

The Government made restriction-testing declarations tonight to cover JC Place Tower 1 and Block 2, Hoi Tak Gardens in Tuen Mun, where the two nurses live, and require people within the restricted areas to undergo compulsory testing.

Dr Chuang added that there may still be a risk of silent transmission in the community. 

"It is still a bit early to say whether the latest outbreak has been contained with the discovery of the recent, even linked, cases because they are not from the quarantine centres. They were detected in the community.

"So they have spent some time in the community and that would also cause some transmission."

In view of one import-related case and four cases tested preliminarily positive, 17 specified premises are included in the compulsory testing notice.

The Government will set up or reopen mobile specimen collection stations at some locations to provide free services for people subject to compulsory testing tomorrow.

The mobile specimen collection stations' service at Lockhart Road Playground in Wan Chai, Handball court in Victoria Park, Arthur Street Temporary Playground in Yau Ma Tei and Tai Po Community Centre will be extended to January 23.

Other locations, at Edinburgh Place in Central, Wong Tai Sin Square, Lai Kok Community Hall in Cheung Sha Wan, Macpherson Playground in Mong Kok, Tsuen Wan Park, On Hing Playground in Yuen Long, Tin Shui Sports Centre in Tin Shui Wai and the mobile specimen collection trucks at Sha Tin, Kwai Tsing, North and Yuen Long districts, will be extended to January 31.

The mobile specimen collection station service at Tung Chung North Park will be extended to February 13.

For information and health advice on COVID-19, visit the Government's dedicated webpage.