Most activities in Singapore can resume on Friday, but the expansion should not be a signal for people to let their guard down, the multi-ministry task force tackling Covid-19 warned yesterday.

Sounding a cautionary note at yesterday's virtual press conference, National Development Minister Lawrence Wong said: "Do not treat phase two as a signal that we can all relax, we can all let our guard down and we can now go out and do all our favourite activities."

Having such a mindset could cause a surge in the number of Covid-19 infections during this phase, and raise the possibility of the country having to reintroduce restrictions, he added.

"I don't think any one of us would like to see (that)," he said.

Under phase two of the reopening, more business and social activities can resume, but individuals must keep a safe distance of at least 1m from others. Where this is not feasible, groups of no more than five persons should be at least 1m apart, with no mixing between groups.

"By all means go out, but limit the number of contacts that we have to a small group and take all the necessary measures," said Mr Wong.

Associate Professor Kenneth Mak, the Health Ministry's director of medical services, said the circuit breaker and the first phase of reopening, during which schools reopened and more workers returned to work, allowed Singapore to improve and fine-tune its contact tracing abilities and the speed of its response.

"(This ensures) that if cases arise or clusters emerge, we would be ready to step in decisively, quickly do contact tracing and quickly throw a ring around to isolate these cases and close contacts to prevent further spread," he said, noting that Singapore had also improved its healthcare capacity to prepare for the possibility of new community clusters emerging as the economy reopens.

"It is therefore important for me to emphasise the need for all of us to continue to be vigilant and to play our part," he said.

Health Minister Gan Kim Yong said it was a delicate balance to strike between allowing economic and community activities to resume, and keeping infection rates under control.

"To succeed, we need the collective effort of every Singaporean to be socially responsible and adhere strictly to safe distancing measures. Minimising prolonged close contact with others, mask wearing and good hygiene practices remain key strategies in the next phase."