Participants in Hong Kong's voluntary universal COVID testing hailed the program as safe and efficient as 126,000 residents took the test on Tuesday, its first day.

As of 8 pm on Tuesday, the free, weeklong program to identify asymptomatic coronavirus cases had received 674,000 registrations.

Swiss finance professional Artur Filipowicz said the process was "hassle－free" after he took the test on Tuesday morning. He said he hoped people would leave behind any political bias and participate in order to help trace hidden carriers of the virus.

Another participant, a woman who wished to be identified only as Shirley, said the medical workers who conducted the test for her were patient and considerate. She said they clearly explained the process and reminded her to rest if she felt unwell afterward.

Local resident Tiffany Zhang, who will take the test on Sept 7, said she thinks the program is really important for the health of every person.

"You have to know whether you're a carrier or whether you have been affected," she said. Zhang said she thinks participants' privacy will be protected and she will recommend that her friends and family members register.

Speaking at a news briefing on Tuesday afternoon, Secretary for the Civil Service Patrick Nip Takkuen said the first day was progressing smoothly with the assistance of 2,000 healthcare professionals and 2,400 administrative staff.

Samples were sent to the BGI Huo－Yan Laboratory in Sai Wan for testing. Positive results will be retested by the Center for Health Protection and confirmed cases will be reported as early as Thursday, according to a CHP official.

Nip said that 32 of the 141 testing centers have been fully booked from Sept 1 to 7, adding that the government will increase the quota for the centers starting on Thursday.

After being tested on Tuesday with other high－ranking officials, Hong Kong Chief Executive Carrie Lam Cheng Yuet－ngor said the program would help to fight the pandemic, and it would help meet local people's expectations to resume normal social and economic activities as soon as possible.

Lam called on those who remain skeptical to take an objective, impartial view of the program and to give it their utmost support. She again urged medical workers who have called on residents to boycott the program to value their professionalism and stop misleading the public.

Some officials of the central government's liaison office in Hong Kong and their family members also took part on Tuesday. After being tested, Chen Dong, the office's deputy director, said that from the experience of the mainland and overseas, mass testing is the most effective way to cut transmission. As part of the Hong Kong community, the office is obliged to participate, he said.

The city on Tuesday reported 12 new cases, bringing its total to 4,822.

Secretary for Education Kevin Yeung Yun－hung encouraged parents and teaching and administrative staff at schools to take part, saying that wider participation will create more favorable conditions for the resumption of classes. Earlier, the government announced that schools would reopen on a phased basis starting on Sept 23.

Wilson Chen and Wu Yufei contributed to this story.