China will expand testing for the novel coronavirus to cover key groups of people as part of measures to curtail COVID-19 while also ensuring normal work resumption, according to a guideline released by the top health authority on Monday.

Mandatory nucleic acid testing for the virus should cover the key groups, including close contacts of confirmed COVID-19 patients, people entering China from overseas, patients at fever clinics, patients to be hospitalized, medical workers and nursing home staff, the National Health Commission said in the guideline.

Authorities across China should expand testing capacity to ensure all others can receive a test if they want to. They can also determine priority groups that should be tested based on their own conditions, the guideline said.

Expanded testing of the virus in the population can help consolidate the fruits of domestic COVID-19 control and prevention while facilitating movement of the population to promote the resumption of production and education, the commission said.

The epidemic has been kept well under control in China, with the number of new confirmed cases reported daily remaining no more than double digits since March.

With increased testing capacity and restoration of production and work, places across China have been increasing COVID-19 testing for groups with higher risks to eliminate the chances of new outbreaks.

In Wuhan, capital of Hubei province, 9.9 million residents－the vast majority of the city's population－received nucleic acid tests between May 14 and June 1, resulting in 300 asymptomatic cases identified, according to the city government.

The mass testing was conducted several days after the city reported six new confirmed COVID-19 cases, after seeing no new cases for more than a month.

In the guideline released on Monday, the National Health Commission urged local health authorities to accelerate improving virus testing capacity to meet the demand.

All tertiary hospitals, hospitals that specialize in infectious diseases, disease control and prevention centers at county levels or above and customs across China should be capable of providing COVID-19 testing services, while secondary hospitals, specialized hospitals and maternal hospitals should gradually improve their labs so they will be able to conduct such tests step by step, the guideline said.

Authorities in border cities that lack medical resources and face high pressure on epidemic control should provide support to key institutes in the cities to help them improve testing, and mobile testing labs should be used if necessary, according to the guideline.

Major institutions such as the centers for disease control and prevention should intensify training for testing staff to ensure quality and standards of testing, and local governments should encourage the research, development and application of faster and accurate testing technologies and equipment, it said.

Health authorities are also required to intensify supervision over quality control and biosafety of testing labs, and ensure privacy of test receivers, the guideline said.