Hong Kong has seen a slight drop in new Covid infections with 628 cases and 26 deaths reported yesterday - with the new cases including five teachers and two students who tested positive before going to school - down from 668 infections on Wednesday.

Of the fresh cases, 25 were imported. The 628 tally came from 311 picked up in rapid tests and 317 in PCR tests, which included the imported cases.

The Centre for Health Protection's principal medical and health officer, Albert Au Ka-wing, said 250 schools have resumed in-person classes and that it had received seven reports of infection from six different schools yesterday.

Two of the five infected teachers work in the same school, but Au does not think their infections are connected. The two students are from different schools.

However, five of the seven had gone to school on Tuesday and Wednesday, testing negative those days.

"There are still risks of infection in the community so it's within expectation that as more schools resume classes, more pupils will report infections from the community," he said. "Most importantly, we have prevented infected pupils and teachers from returning to school to minimize the risk of transmissions on campus."

Au said Korean Air's flight KE607 from Seoul is suspended until next Thursday after a passenger tested positive and several others failed to comply with health rules for arrivals.

That goes too for Cathay Pacific flight CX100 from Sydney after four passengers tested positive on arrival Wednesday.

On the "recovery code" registrations, Au said data for all 1.18 million people infected in the fifth wave had been uploaded and denied a report that said only 800,000 records ha been included.

Undersecretary for food and health Chui Tak-yi said authorities will continue to be on the alert for community outbreaks now that social distancing measures have been eased.

"Premises have reopened and people may lower their guard thinking outbreaks have stabilized," Chui said. "But law enforcement teams will step up inspections and prosecutions in the meantime because we don't want a rebound in cases."

Infectious disease expert Ho Pak-leung said it is safe to relax social distancing measures as long as people comply with health regulations.

Ho also proposed distributing additional consumption vouchers to vaccinated seniors to boost jab coverage in the age group.

Meanwhile, state media People's Daily published a commentary yesterday on the SAR's outbreaks and said the ongoing fifth wave is coming under control.

But it said the outcome did not come "naturally," but as a result of full support from the central government and efforts by SAR authorities and the public. The commentary further said the city must stick with the "dynamic zero" strategyfor the border with the mainland to be reopened.

Cases in schools are expected as there is still risk of infection in the community, says Albert Au.

Seven infected as 250 schools reopen