SINGAPORE - After a 21-hour journey that included a layover in Paris, graduate student Lim Ying Xuan arrived at a relatively empty Changi Airport on Friday (March 20) where he quickly collected his luggage and headed straight to a relative's vacant flat, where he would be spending the next two weeks alone.

His family had stocked the fridge with groceries and daily essentials for the 25-year-old University of Cambridge history student to serve out his 14-day stay-home notice at the four-room Housing Board unit in Punggol.

"I'm isolating myself and treating it as if I have the virus. I don't want to put my family at risk because within the UK, we don't know who has the virus and who doesn't," Mr Lim told The Straits Times over the phone, acknowledging it was "lucky" a relative was willing to let him stay in the flat.

His parents, who are in their 60s, occasionally drop off food at his front door. Mr Lim, who said he is feeling well, only opens the door and waves to them when they are at the lift landing some metres away.

Mr Lim is one of many Singaporeans studying overseas who have returned home in the past week, following an advisory issued by the Ministry of Foreign Affairs (MFA) on Tuesday to do so, as the number of Covid-19 cases around the world increase rapidly.

Since Saturday, Singaporeans and residents returning to the country have to serve a mandatory 14-day stay-home notice. All short-term visitors will no longer be allowed to enter or transit through Singapore from 11.59pm on Monday.

"The moment the MFA issued the advisory, everyone around me who had lingering doubts about whether or not to go back made their decision. I think it was quite a relief for many of us because every extra day you're there adds to the tension," said Mr Lim.

What ensued was a "mad rush" to book a one-way flight ticket, pack four years' worth of belongings into two bags and settle a number of administrative tasks, he added. He does not expect to return to the UK as he is in his final year.

Mr Lim now monitors his temperature twice daily and records it on a whiteboard which has a countdown to the day he can step out of the house.

Some returning overseas students said it was a relief to return to Singapore.

At the beginning of the week, fine arts undergraduate student Joshua Lau, 22, said he and his sister Deborah Lau, 23, were still debating whether to leave London, as flight prices were fluctuating every hour.

"But when we stepped into Changi, it was a huge mental relief. Our fear was if we had gotten sick in London, we wouldn't be able to get proper healthcare because we're international students," said Mr Lau, who attends Central Saint Martins in London. His sister is an arts and culture management postgraduate student at King's College.

He added that he knows of at least 15 other Singaporean students who have flown back home this week.

The flight home was not without drama for Mr Lau, who said some travellers at Gatwick Airport where he was taking his flight had on hazmat suits and raincoats.

He and his sister only wore masks on the flight, as that was all they had.

Back in Singapore, they disinfected their luggage and shoes before stepping into the house and now spend most of their time in separate bedrooms.

"If I want to talk to my family in person, we'll stand a distance away. Hugs can wait; what's important is that we're all back together safely," said Mr Lau.

National University of Singapore medical school student Shanisse Tsai, 22, shares the same sentiment.

Ms Tsai, who was in Boston for a four-week internship programme at Harvard Medical School, decided to self-isolate for two weeks despite having arrived a day before the stay-home notice kicked in.

"I went through the airports and various points of contacts, so even though it's not mandatory for me to stay home, I think the socially responsible thing to do is to isolate myself," she said.

She is working on a research project in place of the now-cancelled internship programme, which she had only completed two of the scheduled four weeks. Her family members leave her meals outside her door.

Ms Tsai had initially planned for a two-week vacation after her internship and had bought tickets to the now-postponed music festival Coachella in California as her "last hurrah" before her final year.

"At first it was quite disappointing to leave because the internship position was really hard to get. But as the situation got more serious in Boston, nothing beats the anticipation to get home; I just wanted to come home as soon as possible," she said.

Ms Tsai has started sharing her stay-home experience on social media in addition to keeping touch with her friends over video calls.

She said: "I'm vlogging my life in this small space so after 14 days, I can look back to see what I did and help other people think of things to do in their rooms."