Two travellers from South Africa have tested "preliminarily positive" for the Omicron variant of Covid-19 after landing in Singapore, the Ministry of Health has said.

Two passengers who arrived in Singapore from South Africa on a Singapore Airlines (SIA) flight SQ479 have tested "preliminarily positive" for the Omicron variant on Wednesday, the MOH here said on Thursday.

"Both cases were isolated upon arrival in Singapore on December 1, and had not interacted in the community," Channel News Asia reported, quoting the ministry.

"There is currently no evidence of any community transmission from these cases," the MOH added. The two travellers, who arrived from Johannesburg, are recovering in isolation wards at the National Centre for Infectious Diseases (NCID).

Both of them are fully vaccinated and have "mild symptoms of cough and scratchy throat", it said.

One is a 44-year-old Singapore permanent resident who arrived in the city-State from Mozambique, transiting through Johannesburg. His pre-departure test in Mozambique on November 29 was negative for Covid-19, said MOH.

The other case is a 41-year-old Singaporean woman who arrived from South Africa. Her pre-departure test in Johannesburg on November 29 was negative for Covid-19.

They had undergone a polymerase chain reaction (PCR) test upon arrival in Singapore, and were immediately taken to a stay-home notice dedicated facility while waiting for their test results, said MOH. Upon confirmation of Covid-19 infection, they were taken to NCID.

"Their PCR test results have revealed the presence of S-gene Target Failure which may be associated with the Omicron variant. The National Public Health Laboratory is conducting whole genome sequencing to confirm the variant," said the Ministry.

Contact tracing

Contact tracing is ongoing and all 19 other passengers who were on the same flight have tested negative for Covid-19, said MOH.

The passengers were quarantined on arrival and are serving their stay-home notices at designated facilities. They are also "subjected to a testing regime", including an on-arrival PCR test and a stay-home notice exit PCR test.

"Other close contacts of these cases, if any, will be placed on 10-day quarantine at designated facilities and undergo PCR tests at the start and end of their quarantine," said the Health Ministry.

All patients suspected or confirmed to be infected with the Omicron variant will be taken to NCID for isolation and clinical management. They will not be allowed to undergo home recovery.

"It is important for everyone to continue to play their part and remain vigilant to mitigate the spread of Covid-19," said MOH.

SIA told Channel News Asia that it is unable to reveal any information about the passengers and crew members due to confidentiality reasons.

It said the pilots and crew who were on the flight have undergone Covid-19 tests, and are in self-isolation, in accordance with guidance from the authorities.

"SIA will assist the health authorities in all necessary contact tracing efforts," it said.

Since 11.59 pm on November 27, all long-term pass holders and short-term visitors with travel history in the past 14 days to Botswana, Eswatini, Lesotho, Mozambique, Namibia, South Africa and Zimbabwe have not been allowed to enter or transit in Singapore.

Meanwhile, Singapore reported 1,101 new Covid-19 cases and nine deaths linked to the coronavirus on Thursday.

The fatalities, aged between 56 and 99, had various underlying medical conditions, said MOH.

Among the new cases, 1,050 infections were from the community (local), 41 cases from the migrant workers' dormitories and 10 cases who arrived here from abroad.

As of Thursday, Singapore has reported 2,67,150 Covid-19 infections and 735 coronavirus-linked deaths since the start of the pandemic.