Officials on Saturday locked down two residential blocks in Diamond Hill for overnight testing.
The “restriction-testing declaration” on Blocks Two and Three of Bel Air Heights took effect at 4 pm and was expected to finish at around 1 pm the next day.
Authorities said they issued the order after considering the Covid-19 viral load in sewage samples from the building and relevant positive cases.
Meanwhile, the lockdown of Kit Yat House at the Yat Tung Two Estate in Tung Chung ended on Saturday morning.
Nearly 900 people were tested and no positive cases were found.