If you are leaving the house to pick up essential items or to exercise, do it alone and don't turn it into a family affair, National Development Minister Lawrence Wong said yesterday.

But nothing beats staying home, he added. "Yes, we can take precautions like safe distancing and the wearing of masks, but the best way to beat the virus is to stay home."

Speaking at a virtual media conference, he said: "If you need to go out to buy food, to buy groceries, go out alone. Don't turn this into an occasion for a family outing. And if you need to go out to exercise, exercise alone and in your own neighbourhood; don't travel out to exercise."

Earlier advisories had allowed members of the same household to work out outdoors together.

But the minister now urges residents to go solo when going out.

During the circuit breaker period, all carparks in gardens, parks and nature reserves will also close, said the National Parks Board last night.

Minimising movement is critical to limiting the spread of the coronavirus, Mr Wong said. "We call on everyone to do this, because it is the best way to protect yourself and your family members."

Singapore is now two weeks into the circuit breaker period for keeping people at home. Non-essential services have been shut, while social gatherings and dining in at eateries are banned.

There have been positive results so far, but the battle against Covid-19 will be a prolonged one, and Singaporeans must continue to hunker down, said the minister, who is co-chair of the multi-ministry task force leading the fight against the virus.

"Remember, the virus spreads through people, through our contacts with others, when we go out and touch surfaces, and then our hands touch our faces," he added.

Meanwhile, stiffer social distancing measures were announced yesterday, including entry restrictions at four wet markets and the closure of some businesses that had earlier been deemed essential.

These new restrictions will remain in place until May 4, after which they may be adjusted as the circuit breaker continues for another four weeks, till June 1.