SHANGHAI, June 11 (Xinhua) -- Shanghai reported six new imported COVID-19 cases and zero increase in locally transmitted COVID-19 cases on Wednesday, the municipal health commission said Thursday.

The imported cases included two Chinese nationals and four Pakistanis. The two Chinese nationals departed from the United States and India, and arrived at Shanghai Pudong International Airport on June 8 and 9 respectively. They showed symptoms during the isolated observation period and were confirmed as COVID-19 patients.

The four people from Pakistan departed for Shanghai on June 2 and arrived in Shanghai on the same day, and later confirmed as COVID-19 patients after showing symptoms.

The six patients have been sent to a designated hospital for medical treatment, while 138 close contacts on the flights have been put under concentrated quarantine.

By Wednesday, Shanghai had registered a total of 343 confirmed imported cases. Twelve of them remain hospitalized and the rest were discharged from hospital after recovery, according to the commission.

The municipality had reported 341 locally transmitted confirmed cases by Wednesday, including seven deaths.