Infectious disease expert Leung Chi-chiu has cautioned against relaxing social distancing measures despite a recent drop in new Covid-19 infections in Hong Kong, saying any easing of gathering rules could result in a rebound in cases in several weeks' time.

Speaking on an RTHK programme, Leung said Hong Kong has seen a decrease in the number of new infections since mid-December.

But he said the decline is too slow, with new local cases dropping by 20 percent on average each week.

He also said the recent data may not fully reflect any transmissions over the Christmas holiday period.

The specialist in respiratory medicine said it would be hard to resume normal school and work arrangements for now.

He added that requiring students and teachers to get regular Covid-19 tests, as suggested by some lawmakers and educators, may not be enough to stop the spread of the coronavirus.

Leung said social distancing measures could be partially eased if daily infections drop to single digits, though large-scale events, such as religious gatherings and performances, should remain off-limits.

He said the city must also be on the alert for any spread in the community of a more contagious strain of Covid-19 first discovered in Britain.