The Centre for Health Protection today said it is investigating seven additional COVID-19 cases, of which three are imported, three are epidemiologically linked with imported cases and one is locally infected.

Six of the cases involve mutant strains, while the viral load of the remaining case is insufficient for mutation tests.

One of the local cases involves a 23-year-old woman who works at Little Boss pet shop in Causeway Bay.

Together with the Agriculture, Fisheries & Conservation Department, the centre went to the pet shop this morning to collect samples from the environment and the animals to ascertain possible sources of infection.

According to a preliminary analysis of the patient's whole genome sequencing, her sample carries the Delta AY.127 strain, which has not yet been found to be related to other cases.

The three cases epidemiologically linked with imported cases live together in Coral Court, North Point. One of them is a 17-year-old male and the other is a girl aged 11. They are family members of an earlier confirmed case, a 19-year-old man living in Yau Tong. The remaining patient is a 46-year-old foreign domestic helper who sometimes visits the 19-year-old's home.

At a press briefing this afternoon, the centre’s Communicable Disease Branch Head Dr Chuang Shuk-kwan said there are less than 20 preliminary positive cases, including a family member of the trio.

Seperately, nine cases are linked with an earlier case involving a 43-year-old Pakistani woman who was confirmed positive on the 26th day of her arrival in Hong Kong.

Dr Chuang said the centre has taken more than 60 environmental samples from the Silka Seaview Hotel Hong Kong in Yau Ma Tei where the woman underwent quarantine. Some samples collected from the purifier outside room 413 and air exhaust vents in the toilet tested positive.

Meanwhile, the Government made a restriction-testing declaration covering Po Wah Court in Cheung Sha Wan and Kui Wo House in Tai Po this evening, where preliminary positive cases live.

People within these two restricted areas have to undergo compulsory testing by 12am.

In view of two import-related cases and three cases that tested preliminarily positive, seven specified premises are included in the compulsory testing notice.

The Government will reopen a number of mobile specimen collection stations to provide free services for people subject to compulsory testing tomorrow.

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