Photo taken on March 27 shows the centralized isolation treatment point in Pudong Expo Area in Shanghai. The city carried out a staggered lockdown starting on Monday in Pudong and Puxi (divided by the Huangpu River) in turn and mass nucleic acid testing will be conducted in the city covering over 6,340 square kilometers and with a population of over 24 million to cut out hidden transmission routes in communities and curb the rapid spread of Omicron. (Photo: Hu Gong)