Passengers arriving in Singapore with travel history to Botswana, Eswatini, Ghana, Lesotho, Malawi, Mozambique, Namibia, Nigeria, South Africa and Zimbabwe within the past 14 days will come under the country's Category IV border measures from 11.59 pm on Sunday.

Meanwhile, the Ministry of Health (MoH) said it expects a new wave of local cases "soon" given the higher transmissibility of the Omicron variant.

"In the coming days and weeks, we should expect more community (local) cases and rapid doubling of cases. This is again a process we need to go through, in order to live with Covid-19," it said.

"However, the peak of the wave can be blunted and we can avoid overwhelming our healthcare system again if everyone plays their part to get their vaccinations and booster doses, self-test regularly and self-isolate if tested positive," the Channel News Asia quoting the MoH said.

In particular, those who have recently arrived from overseas or been in contact with an infected person should reduce their social interactions.

"We have done whatever we can to prepare ourselves for it; especially in administering boosters to our population and starting vaccinations for our children. We seek the cooperation and understanding of everyone, as we weather through an Omicron wave in the next one to two months," the channel quoting the ministry said.

Instead of being isolated in dedicated facilities by default, Omicron cases will be placed on home recovery or treated at community care facilities depending on their clinical presentation, the channel reported.

This means the travellers with links to these countries must take a polymerase chain reaction (PCR) test within two days before departure to Singapore, as well as an on-arrival PCR test. They will also have to serve a 10-day stay-home notice at a dedicated facility. Another PCR test will be administered at the end of their quarantine period.

Previously, long-term pass holders and short-term visitors with recent travel history to these 10 African countries were not allowed to enter or transit following initial reports on Omicron cases there. Singapore citizens and permanent residents returning from these countries would have to serve a 10-day stay-home notice at a dedicated facility.

The MoH said it initially adopted a "more cautious risk containment approach" to reduce the spread of the Omicron Covid-19 variant into Singapore.

"The Omicron variant has since spread widely around the world," the ministry said, adding that Singapore is updating its travel restrictions accordingly.

"As the global situation evolves, we will continue to adjust our border measures in tandem with our roadmap to becoming a Covid-resilient nation,” it said.

"Current observations from affected countries and regions suggest that the Omicron variant is more transmissible than currently circulating variants. Globally, the Omicron variant has overtaken the Delta variant as the predominant variant in numerous countries, such as the UK and Denmark," it added.

Available data suggests that Omicron infections face reduced risks of hospitalisation and severe disease compared to Delta infections, the MoH added.

"Locally, our Omicron cases have so far not been severe as well, none has required intensive care or oxygen supplementation, although this may be partially due to most cases being fully vaccinated and from younger age groups," it said.

Preliminary estimates from overseas studies also indicate that two doses of mRNA vaccines reduce the risk of symptomatic infection from Omicron by about 35 per cent. The risk is further reduced to about 75 per cent lower for individuals with a primary and booster mRNA regimen.

"There should be better protection against severe infection and death due to cellular immunity and other factors," said the MoH.

"It is therefore important for us to press on with our booster vaccination programme to enhance protection against infection and severe disease,” it said.

Also, Omicron cases in Singapore will be placed on home recovery or treated at community care facilities depending on their clinical presentation, instead of being isolated in dedicated facilities by default, the ministry said.

"International evidence indicates that the Omicron variant is likely to be more transmissible but less severe than the Delta variant, and that vaccines, especially boosters, retain substantial protection against hospitalisations caused by Omicron," the channel quoting the MoH said.

"In the last week, we had several unlinked Omicron cases as well as clusters in the community. This was not unexpected given the high transmissibility of the variant,” the ministry said.

Based on the authorities' "updated understanding", Omicron cases will be allowed to follow protocols 1-2-3 as with other Covid-19 cases, it said.

As of Saturday, Singapore has detected 546 confirmed Omicron cases comprising 443 imported cases and 103 local infections.

On Sunday, Singapore reported 209 new Covid-19 cases, 100 of which were imported or those arriving here.

There was also one fatality, taking the country's death toll from coronavirus complications to 822.

As of Sunday, Singapore has recorded 2,77,764 Covid-19 cases since the start of the pandemic.