With a resurgence in Covid-19 infections in the city, the Hong Kong government will expand mandatory testing and extend current restrictions that were due to expire this week so as to keep the pandemic under control.

The city recorded 56 confirmed cases yesterday, bringing the tally to 9,720 and 165 deaths.

Of the daily figure, all but one are local cases, 23 are from unknown sources, and 31 are from densely populated Yau Tsim Mong, comprising Yau Ma Tei, Tsim Sha Tsui and Mong Kok districts.

Pressure is mounting for the authorities to contain the spread in the area as more than half of the 60 patients who were found positive in preliminary testing are from this cluster. On Monday, the daily number of new cases peaked at 107 - the highest in a month.

"This shows that we still have transmission chains across the territory," Chief Executive Carrie Lam said yesterday. "So what we need to do now is join hands and curb transmission as much as possible."

Health officials yesterday said that residents in a government-designated "core zone" in Jordan and Yau Ma Tei will have to undergo compulsory testing even if the buildings they live in have no reported case. The core zone comprises at least 70 buildings identified as having "appalling poor environmental hygiene" or have no property management services.

So far, more than 13,000 residents of the area have been tested. Mandatory testing has been expanded to nearby Sham Shui Po, and residents in buildings that have just one confirmed case in the past 14 days will also get tested.

The government added that compulsory testing will also apply to those living in buildings where sewage pipe samples are found to have the coronavirus.

"All in all, we'll be stepping up our efforts in testing and identification so that we can identify confirmed cases as soon as possible and curb transmission chains," Mrs Lam said.

More residents at a Chai Wan public housing block will be evacuated after over a dozen infections were reported. Health experts had said it could be due to vertical transmission within the building as a result of leaking sewage pipes.

Officials said the government will ban visitors from Brazil and Ireland from flying into Hong Kong, given the severity of the pandemic in those countries.

Among the existing measures that will be extended for a week until next Wednesday is the work-from-home arrangement for civil servants. Various businesses - including gyms, beauty parlours and bars - remain shut, while the cap on public gatherings at two and the ban on dining in at eateries from 6pm remain.

Schools, which have been shut for most of last year with learning moved online, will remain closed till after the Chinese New Year holiday, which ends on Feb 15.

Yesterday, Secretary for Food and Health Sophia Chan said the government will allow the annual Chinese New Year fairs but strict rules will be imposed. This is a U-turn from a previous decision. She noted that the fairs will now be smaller in scale, with fewer stalls spaced farther apart and crowd control management in place.

Meanwhile, the advisory panel on the Covid-19 vaccine said on Monday that it will recommend to the government that the Pfizer-BioNTech vaccine be approved for use in Hong Kong.