Hong Kong started a mass coronavirus testing campaign on Tuesday, with samples being taken in 141 collection centres across all 18 districts of the city.
After testing started at 8.00 a.m. (0000 GMT), more than 10,000 people were tested in the first two hours alone, the South China Morning Post reported.
Around 600,000 residents had signed up online for the free tests as of Tuesday.
Meanwhile, the number of new COVID-19 cases in Hong Kong dropped to single-digit numbers for the first time in a week.
Health officials reported nine new confirmed cases for Monday, of which seven were locally acquired.
Just two had no known sources – a woman, who is 39 weeks pregnant, and a 75-year-old man, who works at a factory plant on Prince Edward Road West, the public broadcaster RTHK reported.