Health officials say three residential buildings are under overnight lockdown.

They said a lockdown is in effect at Ha Kwai House in Kwai Chung Estate, after a test result involving a mutant, which they didn't identify.

They also noted that several people in Kwai Chung Estate had tested positive for Covid recently. They expect to complete the exercise by about 7am.

A lockdown is also in effect for the Hing Fung Building in Sham Shui Po after a resident tested positive for a mutant coronavirus strain.

Officials didn't identify the variant, but said they expect to complete the operation by about 7am.

They also said Fu Tak House in Tai Wo Hau Estate has been locked down - excluding ground floor shops. They said they expect the operation to be completed by about 7.30am.