Police in Hong Kong imposed nearly HK$5 million ($643,000) in COVID-related fines over the long Easter weekend as clear weather drove crowds to city parks and reopened beaches for the five-day holiday.

Fines were handed out to 980 residents and more than 14,000 people were cautioned by Leisure and Cultural Services Department authorities for gathering in groups of more than four and not wearing masks in public.

Nearly half the fines were issued in the Kowloon West area - which includes Sham Shui Po and Yau Tsim Mong. Unlicensed bars, party rooms and illegal gambling halls were targeted, according to the police.

Failure to wear masks, practice social distancing or comply with mandatory testing is a punishable offence that carries an HK$5,000 fine - up from HK$2,000 last year.

Hong Kong recorded seven coronavirus cases Tuesday - the majority of which were imported, leading officials to consider a ban on incoming flights from countries with COVID variant strains.

At the same time, the compulsory isolation period for arrivals from New Zealand, Australia and Singapore - three countries with low daily case counts and no virus variants - will be lowered to 14 days from 21 Friday.

New coronavirus strains have also put into question the need for the roughly 7.5 million doses of AstraZeneca vaccine ordered by the Hong Kong government.

Developed in Britain by a Cambridge-based medical group, the AstraZeneca jab may be less effective against fresh COVID variants, according to researchers, leading local authorities to reconsider its value.

"We have enough vaccines for the whole Hong Kong population at the moment...I think we should actually keep the resources and watch out for any new developments," government adviser David Hui said on a radio show Wednesday.