“We cannot exclude the possibility that the shopkeeper was in fact actually infected from the hamsters,” said Edwin Tsui, a controller at the Centre for Health Protection.

 “If you own a hamster, you should keep your hamsters at home, do not take them out,” department director Leung Siu-fai said at a news conference. “All pet owners should observe good personal hygiene, and after you have been in contact with animals and their food, you should wash your hands.”

“Do not kiss your pets,” he added.

As a precautionary measure, customers who purchased hamsters from the store after Jan. 7 will be traced and be subject to mandatory quarantine and must hand over their hamsters to authorities to be put down, officials said.

They said all pet stores in Hong Kong must stop selling hamsters and that about 2,000 small mammals, including hamsters and chinchillas, will be killed in a humane manner.

Customers who bought hamsters in Hong Kong from 22 December will be subject to mandatory testing and are urged not contact others until their tests have returned negative.

If their hamsters test positive, they will be subject to quarantine.

Hong Kong’s Society for the Prevention of Cruelty to Animals said it was “shocked and concerned” by the decision to kill the animals, and urged the government not to “take any drastic action before reviewing its approach.”

Hong Kong has been grappling with a local omicron outbreak traced to several Cathay Pacific crew members who dined at bars and restaurants across the city before testing positive for the omicron variant.

The government announced late on Monday that two former flight attendants have been arrested for leaving their homes during quarantine and later being confirmed to have coronavirus infections. It did not identify their employer, but said the two arrived from the United States in December and “conducted unnecessary activities” while under medical surveillance.

The arrests came after Cathay Pacific said it had fired two crew members for breaching coronavirus protocols. It previously apologised and called their actions “extremely disappointing.” The company had to cut back on flights — both passenger and cargo — in January because of tightened virus curbs.

The two have been released on bail and will have their case heard in court on 9 February. If convicted of violating anti-epidemic regulations, they could face up to six months’ imprisonment and a fine of up to 5,000 Hong Kong dollars.

Previously in Hong Kong, some air and sea crew members could isolate at home under quarantine exemptions. Regulations were tightened on 31 December to require crew members to isolate in a designated quarantine hotel for about a week.