HONG KONG - To counter the spike in local Covid-19 infections, the Hong Kong government is expanding social distancing measures to include compulsory wearing of face masks on public transport and a night-time ban on dining out, after a round of tightening last Thursday (July 9).

The government added a new measure that stipulates that all passengers taking public transport must wear face masks from Wednesday. Drivers of cabs or buses can refuse a customer who does not wear one. Those who flout the mask rule can be fined up to HK$5,000 (S$898).

At the same time, dining in at all eateries will be banned from 6pm to 5am, and only takeaways allowed then. The number of patrons at each table is capped at four.

The four-person cap for gatherings will also be reinstated, down from the limit of 50. Events such as weddings and religious gatherings will have to adhere to the limit or be cancelled. Venues under a dozen categories, including gaming centres, bars, gyms and cinemas, will shut for seven days.

To beef up cross-border measures, those flying to Hong Kong from high-risk areas will have to show they tested negative before boarding the plane.

The health authorities on Monday said they detected 52 new Covid-19 cases, where 41 are local. Of the local cases, the source of infections is not known for 20 of them.

This brings the tally of confirmed cases to 1,521, including eight deaths.

Hours after the health briefing, Chief Executive Carrie Lam said that over the past eight days, Hong Kong added 182 local cases, of which the source of infections of 54 cases was unknown.

"We don't want all our earlier efforts in containing the virus to go down the drain," said Mrs Lam, who assured that the city has a "rather sufficient" supply of face masks.

Testing for the virus would be ramped up from 7,000 to 8,000 per month, with the government providing free tests for some 400,000 staff in eldercare homes, restaurants and property management, as well as cab drivers.

The authorities said the latest cases involve a growing cluster in an elderly home in Tsz Wan Shan, an outbreak at eatery Dim Sum Square in Sheung Wan, as well as a nurse in Yau Ma Tei.

The Red Cross said it is following up on the case of an infected person who had donated blood at its West Kowloon centre on July 5.

Other new patients include a construction worker, real estate manager, a ParknShop cashier and cab drivers.

Infectious disease experts in the city have been urging the government to tighten measures amid the spike in cases, saying the latest outbreak is more dangerous than what the city experienced in March.

The surge in cases prompted the suspension of a string of activities, while companies switched back to work-from-home arrangements.

On Monday morning, the Hong Kong Trade Development Council announced that the Hong Kong Book Fair, set to be held from tomorrow, would be postponed, as would three other fairs.

Officials from the Centre for Health Protection said on Sunday that the pandemic situation has "gone a bit out of control" and they are worried space will quickly run out in quarantine centres if the surge goes on.

Of the 30 local cases mentioned then, more cab drivers have been found to have the virus, while more cases have been reported in a cluster involving an eatery in Jordan.

With many of the new local infections linked to East Kowloon, health officials urged residents in the area to go for testing if they show symptoms.