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

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

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

Police officers attend a ceremony mourning those who died of the coronavirus disease (COVID-19) as China holds a nationwide mourning on the Qingming tomb-sweeping festival, in Wuhan, Hubei province, China April 4, 2020. China Daily via REUTERS

A police officer positions the Chinese national flag at half-mast along Huangpu river in Shanghai, 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. cnsphoto via REUTERS

The Chinese national flag flies at half-mast at Tiananmen Square, as China holds a national mourning for those who died of the coronavirus disease (COVID-19), on the Qingming tomb sweeping festival in Beijing, China April 4, 2020.

Workers observe a moment of silence at a construction site in Shaoyang, Hunan 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 observe a moment of silence on a street 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.

Security personnel wearing face masks stand to pay tribute as China holds national mourning for those who died of the coronavirus disease (COVID-19), on the Qingming tomb-sweeping festival, in Beijing, China, April 4, 2020.

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

A man with a face mask observes a moment of silence on a street 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 observe a moment of silence in front of the Chinese national flag at Tiananmen Square that is flying at half mast, as China holds a national mourning for those who died of the coronavirus disease (COVID-19), on the Qingming tomb-sweeping festival in Beijing, April 4, 2020. cnsphoto via REUTERS

People observe a moment of silence outside Hankou Customs House where the Chinese national flag flies at half mast, 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. cnsphoto via REUTERS

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 stand on the street to pay tribute as China holds national mourning for those who died of the coronavirus disease (COVID-19), on the Qingming tomb-sweeping festival, in Beijing April 4, 2020.

A man with a face mask observes a moment of silence on a street 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.

The Chinese national flag flies at half-mast at the headquarters of the People's Bank of China, the central bank (PBOC), as China holds a national mourning for those who died of the coronavirus disease (COVID-19), on the Qingming tomb-sweeping festival in Beijing, China April 4, 2020.

People holding flowers observe a moment of silence at a memorial event in Beijing 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. cnsphoto via REUTERS

People wearing face masks walk past the Chinese national flag flying at half mast 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 observe a moment of silence on a street 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 man wearing a face mask cries 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 man wearing a face mask salutes during a ceremony where the Chinese national flag is positioned at half-mast, at Tiananmen Square in Beijing 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 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.

The Chinese national flag flies at half-mast during sunrise at Tiananmen Square in Beijing, 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. cnsphoto via REUTERS

A woman wearing a face mask stands at an entrance to a store in Beijing, as China observes three minutes of silence to mourn for those who died of the coronavirus disease (COVID-19), on the Qingming tomb-sweeping festival, April 4, 2020.

The Chinese national flag flies at half-mast near of Beijing Railway station as China holds a national mourning for those who died of the coronavirus disease (COVID-19), on the Qingming tomb sweeping festival, in Beijing, China, April 4, 2020.

People wearing face masks use their smartphones at Tiananmen Square, as China holds a national mourning for those who died of the coronavirus disease (COVID-19), on the Qingming tomb-sweeping festival in Beijing, China, April 4, 2020.

The Chinese national flag flies at half-mast behind a statue of late Chinese chairman Mao Zedong 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.

The Chinese national flag flies at half mast at a ceremony mourning those who died of the coronavirus disease (COVID-19) as China holds a nationwide mourning on the Qingming tomb-sweeping festival, in Wuhan, Hubei province, China April 4, 2020. China Daily via REUTERS