HONG KONG — Hong Kong authorities say nearly half a million people have registered for a free universal coronavirus testing program that is due to begin Tuesday.

Residents registering online have already booked out 80 testing sites located in gymnasiums and community centers for the initial day of the program, according to the government’s website. It said other centers still have places if the number of those signing on rises above the 420,000 registered as of late Sunday.

Hong Kong launched the program in an effort to track down paths of infection that have consistently added to case numbers despite strict social distancing and other measures imposed on the densely populated semi-autonomous Chinese city of 7.5 million. All who wish to be tested can do so at no cost.

Hong Kong on Sunday reported another 15 cases of coronavirus and one additional COVID-19 fatality, bringing its totals to 4,801 cases and 88 deaths.

Mainland China on Monday reported 17 new cases found over the previous 24 hours, all of them brought from outside the country. China currently has 237 people being treated in hospital for COVID-19, with another 340 in isolation after testing positive for the virus without displaying symptoms. China has reported 4,634 deaths among 85,048 cases of COVID-19 since novel coronavirus was first detected late last year in the central Chinese city of Wuhan.