Shenzhen reported four imported confirmed cases of COVID-19 yesterday.

The confirmed cases, three of Chinese nationality and one of the U.S. nationality, flew to Shenzhen from Los Angeles, the U.S., on Dec. 29. Three of the confirmed cases were the asymptomatic cases previously reported.

They were quarantined upon entry and have been sent to the emergency wards of the Third People’s Hospital of Shenzhen for treatment. Currently, the patients are in stable condition.