China has reported 15 new coronavirus cases while Wuhan, the epicentre of the COVID-19, where over nine million people have been tested in the last few weeks has not registered any asymptomatic case for the first time, the health authority said on Tuesday.

According to China's National Health Commission (NHC), five imported cases and 10 asymptomatic cases were reported in the country on Monday.

So far, 371 asymptomatic cases, including 39 from overseas, were still under medical observation, it said.

Asymptomatic cases pose a problem as the patients are tested COVID-19 positive but develop no symptoms such as fever, cough or sore throat. However, they pose a risk of spreading the disease to others.

Meanwhile, Wuhan which has been reporting a number of asymptomatic cases for a while for the first time reported zero cases on Monday.

The growing number of asymptomatic cases prompted the government to embark on testing of all its 11.2 million people last month. Life has returned to normal in the city after 76-day lockdown to control the virus.

The city so far had 50,340 confirmed coronavirus cases since January this year of which 3,869 people have died.

Health authorities in Wuhan said, zero new asymptomatic cases of COVID-19 were reported on Monday for the first time since the city started publishing the cases of silent carriers but 320 people with the symptoms were still under quarantine in the city.

According to a notice from the Wuhan Health Commission, the city tested more than 60,000 residents on Sunday for asymptomatic infection and all tested negative, state-run Global Time reported.

The result shows that the concentrated nucleic acid testing and screening work in the city has made significant progress, the notice said.

According to the commission, more than nine million residents have been tested as of May 24 since the launch of centralised nucleic acid testing in Wuhan on May 15, completing more than 90 per cent of the whole city's sampling work.

As of Monday, the overall confirmed coronavirus cases had reached 83,022, including 73 patients still being treated, 78,315 people who had been discharged after recovery, and 4,634 people who died of the disease.