SINGAPORE - Thirteen Covid-19 cases who served their stay-home notices (SHN) at Mandarin Orchard Singapore hotel are being investigated by the Ministry of Health after it emerged they could be linked.

Here is more on what happens when travellers serve SHN.

1. Before arrival in Singapore

All travellers must submit a pre-trip health and travel history declaration before arriving here.

Those who are not Singapore citizens or permanent residents (PR) need entry approval from government agencies or certain travel passes to enter Singapore.

Depending on a person's travel history, they will need to comply with different requirements.

Some will need a negative result for an approved Covid-19 swab test taken within 72 hours before departure.

Singaporeans and PRs do not need to take a Covid-19 polymerase chain reaction test before returning here.

2. Arrival in Singapore

On arrival, most travellers will receive an SHN or an electronic monitoring device during immigration clearance or both. The SHN duration can vary between seven and 14 days.

Those arriving from a limited list of countries, including Brunei and Australia, are allowed to take a swab test on arrival. They will have to self-isolate while waiting for their results and do not need to serve an SHN.

Different requirements apply for those that enter Singapore through short-term travel lanes.

3. From airport to SHN facilities

Some travellers from places such as Macau can choose to opt out of serving their SHN in dedicated facilities and choose to serve it at their residential address.

They must meet criteria such as occupying the place of residence alone or only with household members with the same travel history.

Others will be allocated dedicated SHN facilities by officers at the immigration checkpoint.

Transportation will be arranged to take them to these facilities directly from the airport.

Staff at Changi Airport who come into close contact with passengers don full personal protective equipment and are routinely tested for Covid-19.

4. Serving SHN

Hotels used as SHN dedicated facilities need to have strict protocols to separate those on SHN from other guests.

This includes placing them in segregated blocks, wings or floors as well as ensuring the routes they use to get around are clearly separated from that of other guests.

Individuals on SHN cannot leave their rooms during their stay, and rooms are thoroughly disinfected and sanitised after they leave.

These people cannot access common facilities in the hotels too.

During their SHN, travellers will have to take a Covid-19 swab test.

To avoid contact with other people, they have their own room and toilet each, with meals provided to them.

The Immigration and Checkpoints Authority will also conduct checks on travellers placed on SHN through house visits, calls or via WhatsApp.

From Jan 1, costs will no longer be waived for Singaporeans and PRs who last left the country before March 27 and are staying at dedicated SHN facilities.