The Centre for Health Protection today said it is investigating three preliminary positive COVID-19 cases which may carry the Omicron variant, while the Government this evening made a restriction-testing declaration for the buildings where two patients live.

One of the patients is a 76-year-old man living at Wing Chak House, Chak On Estate in Shek Kip Mei. He is a non-household family member of the earlier confirmed imported case who is an aircrew member.

They had lunch with another woman from around 1.30pm to 3pm on December 27 at Moon Palace, Festival Walk in Kowloon Tong.

After his family member tested positive, he was sent to Penny's Bay Quarantine Centre (PBQC) for quarantine on December 28.

His specimen collected the next day tested preliminary positive with a cycle threshold (Ct) value larger than 30 with the N501Y and T478K mutant strains.

He is retired and has no recent travel history. He remains asymptomatic and had received two BioNTech jabs.

The 34-year-old male patient also had a meal at Moon Palace with three family members from around 2.30pm to 4pm on December 27.

He developed a cough on December 29 and attended Tuen Mun Hospital’s accident and emergency department by Light Rail today.

His specimen tested preliminary positive with a Ct value of about 30 involving the N501Y and T478K mutant strains.

He lives in a village house in Tuen Tsz Wai, Lam Tei in Tuen Mun, had no recent travel history and had also received two doses of the BioNTech vaccine.

According to the investigation at this stage, the centre said it could not rule out the possibility that the two patients were infected by the aircrew member during the meal at Moon Palace on December 27.

It added that whole genome sequencing analysis would be needed to ascertain the connection of the three cases.

The centre has requested the restaurant to close the premises for thorough cleansing and disinfection and improving the air change.

The other case involves a 47-year-old man who is a co-worker of another aircrew member confirmed infected with COVID-19 and carrying the Omicron variant.

They arrived together in Hong Kong on December 25 on Cathay Pacific flight CX843 from the US.

After his co-worker tested positive, the man was sent to the PBQC for quarantine on December 28 and tested preliminary positive the next day with a Ct value of about 25 involving the N501Y mutant strain.

He remains asymptomatic and received three doses of the BioNTech vaccine.

He lives in Block A, Hoi Tao Building in Kennedy Town.

The Government made restriction-testing declarations at Wing Chak House in Shek Kip Mei from 7pm and Block A, Hoi Tao Building from 10pm, requesting people within these specified restricted areas to undergo compulsory testing.

The Government aims to finish both exercises at about 7am tomorrow.

The other floors of the village house where the 34-year-old male patient lives will be included in a compulsory testing notice. 

The places where the three patients had visited in Hong Kong during their incubation periods will also be included in the compulsory testing notice.