HONG KONG - The Hong Kong government has moved to tighten social distancing measures, including a ban on dancing in bars and pubs, as the travel bubble deal with Singapore hangs in the balance.

But the first few flights under the travel arrangement will proceed as planned on Sunday (Nov 22), the Civil Aviation Authority of Singapore (CAAS) said on Saturday.

In a release issued on Saturday morning, the Hong Kong government said live performances and dancing in bars and pubs will be banned, while premises like party rooms meant for holding social gatherings will be forced to shut from Sunday for five days till Nov 26.

Business owners who breach these new rules can be fined up to HK$50,000 (S$8,665) and jailed for six months.

Chief Executive Carrie Lam early Saturday echoed the words of health authorities in a Facebook post, saying the pandemic in the city has hit a "severe" stage.

A meeting was called on Friday night and the government has come up with more anti-coronavirus measures that will be announced on Saturday, she said.

"Our priority now is to quickly cut off transmission through testing," she said, adding that she has requested testing of those deemed high risk to be beefed up and for her team to find more ways to encourage voluntary testing.

The development follows a spike in the new Covid-19 infections on Friday which prompted Health Secretary Sophia Chan to warn that Hong Kong has "probably entered into a new wave of cases".

Health officials and the city's infectious diseases experts have for weeks warned about the impending fourth wave of the pandemic, with the latter on Friday saying they believe the new wave has arrived.

Under the deal which was announced in mid-October, the bubble flights will be suspended for two weeks if the seven-day moving average of the daily number of unlinked local Covid-19 cases is more than five for either Singapore or Hong Kong.

The moving average for the territory on Friday was 2.14 but the number of new infections on Saturday will be crucial in determining if the threshold is breached.

The threshold will be exceeded if there are more than 22 unlinked local cases over the next three days. This will trigger a two-day notice period, after which suspension will come into effect, CAAS said on Saturday.

Local media reported that the city recorded 45 new cases on Saturday but it was unclear how many are unlinked local cases.

Hong Kong added 26 confirmed cases as of Friday, bringing the tally of confirmed cases to 5,517 and 108 deaths. A further 40 people were found positive in preliminary testing and authorities noted that many of them are local cases.

The Hong Kong Tourism Commission, in a response to The Straits Times, said that the travel bubble can be adjusted any time by either increasing or reducing designated flights, or suspending them altogether.

If the threshold of five is breached, the travel bubble "will be suspended in two days' time (including the day on which the figure was announced) for two weeks".

"The two governments will notify the airlines and make the relevant announcement," it said, adding that if the figure stayed under five for both cities on the last day of the suspension, the travel bubble can resume the next day.

The tourism commission added that in the event of a suspension of the travel bubble, Singapore citizens, permanent residents or long-term pass holders can return to Singapore from Hong Kong by non-bubble flights but they will be subject to Singapore quarantine arrangements such as the seven-day stay-home notice.

In view of the rise in cases in Hong Kong, CAAS said on Saturday that travellers from Hong Kong, who previously required to take a Covid-19 test only prior to departure for Singapore. will have to go for the upon arriving in Singapore.

In Hong Kong, high-risk groups such as taxi drivers and nursing home staff are required to undergo mandatory testing for the virus, while patients who exhibit symptoms when they visit doctors have to do so too.

On Nov 14, the Hong Kong government had moved to tighten social distancing rules after detecting clusters among taxi drivers and at a Lantau resort.

Since Monday, dine-in services have ended two hours earlier at midnight while the cap on patrons per table was lowered to four from six. In bars and pubs, the number is halved to two. The measures are to last until Nov 26.

Given the popularity of staycations with borders shut, officials are looking to impose at resorts, hotels and guesthouses in each room a four pax max rule - the same limit as public gatherings in Hong Kong.

The government has tightened visiting arrangements for those serving mandatory 14-day quarantine periods after returning from overseas.

It is now considering giving a one-off subsidy to grassroot workers if they are confirmed to be infected.

Separately, the government is dealing with an upper respiratory tract infection outbreak in schools.

Eight cases have been reported in eight primary schools and Prof Chan said that from Nov 23, in-person classes for lower primary school levels (Standards 1 to 3) would be suspended for two weeks. She said classes at all schools may be cancelled if the situation worsened.

This decision on Friday came just over a week after kindergartens were ordered to close for two weeks due to the same nature of infections.