Seventeen buildings in Sham Shui Po, as well as parts of Jordan and Tin Shui Wai were cordoned-off on Tuesday night for mandatory testing.
Results were still being verified for Jordan on Wednesday morning.
Workers visited some 860 households in the biggest operation in Sham Shui Po, although around 200 failed to answer.
The administration had earlier warned that authorities could break into people’s homes and forcibly remove them if they didn’t answer the door during the “ambush-style” operations.
The lockdowns were carried out despite the city reporting the lowest daily number of coronavirus infections in a month on Tuesday. There were 25 new cases.
Over the past two weeks, the government has tested about 10,000 residents in its lockdowns, and found just over a dozen infections.
But Chief Execuive Carrie Lam, who visited the locked-down area of Sham Shui Po on Tuesday, said that success can’t be measured by the number of cases found.
There were similar lockdowns the previous night in Tsim Sha Tsui, Yuen Long, Hung Hom and Yau Ma Tei. No Covid infections were found.