Staff members leave the transfer bus parking lot at the Putong International Airport in Shanghai, east China, March 19, 2020. (Photos: Xinhua)

A staff member checks the information of a passenger entering China at the Pudong International Airport in Shanghai, east China, March 19, 2020.

Staff members check the information of passengers entering China at the Pudong International Airport in Shanghai, east China, March 18, 2020.

Staff members check the information of passengers entering China at the Pudong International Airport in Shanghai, east China, March 18, 2020.

A staff member guides passengers entering China to take transfer bus at the Pudong International Airport in Shanghai, east China, March 19, 2020.

Passengers entering China wait for a transfer bus at the Pudong International Airport in Shanghai, east China, March 19, 2020.

A staff member checks the information of a passenger entering China at the Pudong International Airport in Shanghai, east China, March 19, 2020.