The city reported four locally transmitted COVID-19 cases, 977 local asymptomatic infections, 10 imported patients and four imported asymptomatic cases on Tuesday, said the Shanghai Health Commission on Wednesday morning.Of all the local infections, three confirmed patients and 886 asymptomatic cases were detected during central quarantine, while the rest were found in the screening of high-risk people.4 local casesThe first three patients tested positive during central quarantine while the rest one tested positive when screened as high-risk people.