The Centre for Health Protection says anyone who has been to the locations, during the specified times, must take a nucleic acid test. This includes people who have been fully vaccinated against Covid.
USEFUL LINKS
General Covid-19 situation: https://www.coronavirus.gov.hk/eng/
Covid-19 testing: https://www.communitytest.gov.hk/en/
Compulsory testing notices: https://www.chp.gov.hk/en/features/105294.html
Community Clinics for Covid-19 patients: https://bit.ly/3GXwDXJ
Vaccination programme: https://www.covidvaccine.gov.hk/en/
Hotline for Covid-positive patients: 1836 115