The Centre for Health Protection reported two imported coronavirus cases on Thursday, and one local infection linked to a previous patient.
It marked the sixth consecutive day without an untraceable local infection.
One of the imported cases involved a 43-year-old man who flew to France on May 6 and came back on Sunday. He developed fever during hotel quarantine in the SAR.
Officials believe the man contracted the virus in France but as a precaution, mandatory tests will be ordered for residents of a building in Staunton Street where he lives.
Meanwhile, Chinese University has told students living in its dormitories that they will have to get tested for Covid every two weeks unless they are vaccinated.
The university said students would have to pay for the tests themselves.
Hong Kong has seen a slow uptake in vaccinations. Some 1.1 million residents have now had at least one dose.
The government says an indemnity fund it set up to provide financial support for those who experience serious complications from taking the jabs has so far received 11 applications.