Volunteers from the Blue Sky Rescue team disinfect at the Qintai Grand Theatre in Wuhan, Hubei province, the epicentre of China's coronavirus disease (COVID-19) outbreak, April 2, 2020.

People wearing face masks pay tribute to the deceased in Wuhan, Hubei province, as China holds a national mourning for those who died of the coronavirus disease (COVID-19), on the Qingming tomb-sweeping festival, April 4, 2020.

A worker in a protective suit collects a swab from a construction worker for nucleic acid test in Wuhan, Hubei province, the epicentre of the novel coronavirus disease (COVID-19) outbreak in China, April 7, 2020. China Daily via REUTERS

Volunteers from the Blue Sky Rescue team disinfect at the Qintai Grand Theatre in Wuhan, Hubei province, the epicentre of China's coronavirus disease (COVID-19) outbreak, April 2, 2020.

A resident looks out at a closed entrance of an old residential community in Wuhan, Hubei province, the epicentre of China's coronavirus disease (COVID-19) outbreak, April 5, 2020.

Volunteer drivers sound their horns while observing a moment of silence on a road in Wuhan, Hubei province, as China holds a national mourning for those who died of the coronavirus disease (COVID-19), on the Qingming tomb-sweeping festival, April 4, 2020. China Daily via REUTERS

People wearing face masks pose for pictures by the Yangtze river in Wuhan, Hubei province, as China holds a national mourning for those who died of the coronavirus disease (COVID-19), on the Qingming tomb-sweeping festival, April 4, 2020.

A resident wearing a face mask is seen at an old residential community blocked by barriers in Wuhan, Hubei province, the epicentre of China's coronavirus disease (COVID-19) outbreak, April 5, 2020.

People wearing face masks line up to pay for their breakfast, "Regan Noodle", a Wuhan signature dish of hot dried noodles, at a residential area blocked by barriers in Wuhan, Hubei province, the epicentre of China's coronavirus disease (COVID-19) outbreak, April 2, 2020.

Delivery workers standing amid parcels observe a moment of silence outside a shopping mall in Wuhan, Hubei province, as China holds a national mourning for those who died of the coronavirus disease (COVID-19), on the Qingming tomb-sweeping festival, April 4, 2020. China Daily via REUTERS

People wearing face masks check their mobile phones by the Yangtze river in Wuhan, Hubei province, as China holds a national mourning for those who died of the coronavirus disease (COVID-19), on the Qingming tomb-sweeping festival, April 4, 2020.

People wearing face masks buy vegetables at a street market in Wuhan, Hubei province, the epicentre of China's novel coronavirus disease (COVID-19) outbreak, April 6, 2020. RUETERS/Aly Song

Employees, wearing masks, work on a production line manufacturing display monitors at a TPV factory in Wuhan, Hubei province, the epicentre of the novel coronavirus disease (COVID-19) outbreak in China, April 7, 2020. China Daily via REUTERS

Security guards wearing face masks remove barriers on a street in Wuhan, the epicentre of China's novel coronavirus disease (COVID-19) outbreak, April 5, 2020.

Residents wearing face masks walk dancing at an old residential community blocked by barriers in Wuhan, Hubei province, the epicentre of China's coronavirus disease (COVID-19) outbreak, April 5, 2020.

A grandma and her grandson walk at an old residential community blocked by barriers in Wuhan, Hubei province, the epicentre of China's coronavirus disease (COVID-19) outbreak, April 5, 2020.

Fresh chrysanthemum flowers, a traditional Chinese funeral flower, lie on the banks of the Yangtze River on the eve of the Tomb-sweeping Festival in Wuhan, Hubei province, the epicentre of China's coronavirus disease (COVID-19) outbreak, in Wuhan ,China, April 3, 2020.

A woman wearing a face mask gets out through barriers, which have been built to block buildings from a street in Wuhan, Hubei province, the epicentre of China's coronavirus disease (COVID-19) outbreak, April 5, 2020.