Supermarket shelves across the island were restocked with staple food items yesterday following a surge in panic buying after Singapore's disease outbreak response level went up to orange last Friday.

At a walkabout in Jurong West, Trade and Industry Minister Chan Chun Sing said Singapore has a sufficient stockpile of food and a diverse and trusted supply chain, making the rush for supplies unnecessary.

Rather, such a "survival of the fittest" mentality in a crisis also affects vulnerable groups of society and reflects poorly on Singapore in the world's eyes, he added.

He highlighted four ways the Government was securing the Republic's food supply needs.

One, a national stockpile of food items like rice that can last some time. But the size of this inventory is not disclosed as doing so would compromise Singapore's ability to secure supplies internationally.

Two, diverse sources so that Singapore will not be held to ransom by any single supplier, especially for protein which is sourced from as far as Europe and South America.

Three, Singapore has some local production capability, including over 40 fresh and instant noodle manufacturers, some of whom ramped up supply in recent days.

Four, Singapore works with trusted suppliers, both regionally and globally, to secure its supplies.

Social and Family Development Minister Desmond Lee, who accompanied Mr Chan, welcomed the sense of normalcy they felt on the visit to a market and coffee shops.

"Some were a little unhappy at the rush yesterday to buy more things than people needed... but today they felt reassured that the supermarkets near to their home will be restocked, and are being restocked," said Mr Lee.

Mr Chan added: "If, in a crisis, all of us only take care of ourselves and it's only the strong taking care of themselves, it will be a bad testimony to the kind of society that we want and that we can have."

He added that if Singapore responds well as a cohesive and calm community, it gives others confidence to continue to want to do business with it after the crisis. Otherwise, he said, "we undermine the international confidence in our system, in our society, and that will have long-term implications on us".

Yesterday, FairPrice outlets put up notices to inform customers they could buy only up to four packs of paper products such as toilet paper and tissues, two bags of rice and four pillow packets of instant noodles, so that more people would have access to these items while restocking takes place.

Singapore moved its disease outbreak response up by one level to orange on Friday.

Yesterday, the People's Association announced that 54 per cent of households had collected the masks set aside for them and they will remain available at community centres till the end of the month, after which the rest will be returned to the national stockpile.

The Manpower Ministry also said it had taken action against four work pass holders and six employers who had breached leave of absence requirements in place due to the coronavirus situation.

The work pass holders were repatriated within 24 hours and banned permanently from working here, while the employers will not be allowed to hire work pass holders for two years.

It is the first such action taken since all work pass holders with recent travel history to China were required to serve a mandatory 14-day leave of absence upon their return.

A National University of Singapore student has also been suspended from school for a month after breaching the leave requirements by attending lectures.

Separately, the Health Ministry announced three new cases of the coronavirus yesterday, bringing the total to 43. Local cases now exceed imported ones. All three new cases currently have no known links to existing cases or recent travel history to China.

The first is a Singaporean man, 71, who had visited a church, attended a residents' committee gathering, and picked up his grandchild outside a childcare centre.

The second is a Bangladeshi work pass holder, 39, who had stayed in a Kaki Bukit dormitory.

The third is a Singaporean man, 54, who was in Malaysia on Jan 26.

Of the 43 cases, six are now in critical condition and in the intensive care unit, up from four previously.

Meanwhile, four have been discharged, making a total of six who have recovered.