Hong Kong's toughest social-distancing curbs came into force on Thursday as the city grappled with its worst COVID-19 outbreak, logging 986 new infections and around 800 preliminary positive cases.

Though the city saw a slight decrease in confirmed cases, down from 1,161 on Wednesday, Gabriel Leung Cheuk-wai, dean of the Li Ka Shing Faculty of Medicine at the University of Hong Kong, warned that vigilance should be maintained, calling for more stringent and effective measures to bring the outbreak under control.

Measures that took effect from Thursday included closing religious venues and hair salons, together with already shuttered entertainment venues such as bars, gyms, and beauty salons, until Feb 24, and banning gatherings involving more than two households in private residential buildings.

Meanwhile, patrons aged 12 or above visiting Type D restaurants－where all staff are fully vaccinated－must have received at least one dose of COVID-19 vaccine, with the city's "vaccine pass" pilot program also coming into effect on Thursday.

Type D restaurants are allowed to serve four diners per table, while other types of restaurants are limited to two per table.

From Feb 24, the "vaccine pass" program will expand to government venues and 23 other types of premises, including shopping malls, supermarkets, wet markets, hair salons, religious establishments, nightclubs, massage establishments and sports premises, in a bid to improve the city's vaccination rate.

Apart from those aged 5 to 11, 81.3 percent of Hong Kong residents have received their first COVID-19 vaccine dose.

The government has set a target of 90 percent or above.

On Wednesday, many residents flocked to hair salons to grab the opportunity to have their hair cut.

Ellen Tam Wai-wah, chairman of the Hair and Make-up Stylish Image Designers General Union, estimated that hair salons might lose 70 to 80 percent of their business due to the new measure, and some small salons may have to close down.

Tam said the industry is willing to cooperate with anti-pandemic work, but added she hopes the government will reconsider whether the measures will cause inconvenience to the public and whether they are necessary before implementing them.

The supply of fresh vegetables from the Chinese mainland to Hong Kong, disrupted earlier by infections detected among some cross-border truck drivers, has gradually returned to normal, reaching around 90 percent of the usual level, the Hong Kong Special Administrative Region government said on Thursday.

It said the supply will return to a stable level and vegetable prices will gradually go down after spiking due to the scarcity of fresh supplies in recent days.

The Food and Health Bureau pledged that it will work closely with government departments, the industry and mainland authorities to ensure a stable supply of fresh food to the city.

Facing huge citywide demand for virus testing and early detection, the Hong Kong government deployed over 200 civil servants to maintain order at different testing sites and set up special queues for elderly people, the pregnant and the disabled, Chui Tak-yi, undersecretary for food and health, told a daily press briefing on the pandemic situation on Thursday.