HONG KONG (REUTERS) - Hong Kong authorities said on Sunday (Jan 23) that one hamster surrendered to the authorities by pet owners had tested positive for the Covid-19 virus and that more than 2,200 hamsters had been culled as the city grappled to contain an outbreak.

On Tuesday, officials ordered the killing of hamsters from dozens of pet shops after tracing a coronavirus outbreak to a worker at a shop, and asked people to surrender any bought on or after Dec 22.

While a handful of hamsters had already tested positive for the virus, this latest case is the first involving a hamster in the care of a pet owner that had tested positive.

Despite a public outcry against the hamster crackdown, the authorities urged pet owners to continue to hand over their tiny furry pets, given burgeoning health risks.

"(The government) strongly advises members of the public again to surrender... as soon as possible their hamsters purchased in local pet shops on or after Dec 22, 2021 for humane dispatch," the government said in a statement.

As at Jan 22, a total of 2,512 animals, including 2,229 hamsters, had been “humanely dispatched”, according to a government statement.

Hong Kong leader Carrie Lam earlier told reporters that she understood "pet owners are unhappy" with the killings, but said the biggest priority was to control the outbreak.

The government described the outcry as "irrational".

Thousands of people have offered to adopt unwanted hamsters.

Some scientists and veterinary authorities have said there is no evidence that animals play a major role in human contagion with the coronavirus.

Meanwhile, officials have warned that Covid-19 infections could be growing exponentially in the congested residential area of Kwai Chung on the Kowloon peninsula, as a second building in the district with two thousands residents was locked down on Saturday for five days.

More than 35,000 residents in over a dozen buildings in the area were also ordered to take Covid-19 tests, with Mrs Lam herself visiting the area on Sunday.

Health Secretary Sophia Chan told reporters on Sunday that the city’s strategy of containment would continue.

Some 140 confirmed cases were reported on Sunday, the highest daily number in the financial hub since July 25, 2020.

Mrs Lam urged people to avoid gatherings ahead of next week's Lunar New Year holidays to try to contain the highly infectious Omicron variant.

The situation is testing Hong Kong's "zero Covid-19" strategy focused on eliminating the disease, with schools and gyms already shut, restaurants closing at 6pm and air travel with many major hubs severed or severely disrupted.

Some companies have begun to enact contingency measures.

UBS Group said in a note to its Hong Kong staff reviewed by Reuters that it had "decided to move to work-from-home operations for all except a minimum number of staff who have essential tasks to be completed in the office", given the Omicron outbreak.

A UBS spokesman declined to comment on the memo.

On Friday, officials shut down the first Kwai Chung building after more than 20 cases were linked to it, with food delivered from outside three times a day and mass testing under way.