According to the Centre for Health Protection, the five XBB patients - four women and one man aged between 34 to 65 - were newly inbound to Hong Kong from the UK, India, Thailand, and Singapore, respectively.

The sub-lineage XBB.1 case was first reported in Hong Kong on Monday, involving a woman in her 50s who arrived from the United States on September 25.

Separately, the city logged 4,788 Covid cases today, with 368 imported and nine deaths.

Gilman Siu Kit-hang, assistant professor of Polytechnic University's department of health technology and informatics, is concerns about the new variant to bring more cases across the city this winter.

"It is still unpredictable whether the XBB.1 variant will become dominant in Hong Kong," he said, noting the XBB.1 variant cases account for about one percent of cases worldwide.

Speaking in the press conference on Tuesday, Chief Executive John Lee Ka-chiu emphasised the imported new variant into the city, mentioning it as an uncertain factor against the city's progress to push forward with removing entry restrictions.

However, Ho Pak-leung, a microbiologist at the University of Hong Kong, echoed Lee's speech by claiming the city was well prepared to lift the current three-day self-surveillance for new arrivals, citing the increase of new variants cases was "normal".