Shanghai reported one asymptomatic COVID-19 case on Wednesday, the municipal government announced on Thursday.

Authorities said the asymptomatic case was found to have come into close contact with an imported case that tested positive on Dec 23 during the seven-day self health monitoring period.

The 28-year-old asymptomatic case was then placed under hotel quarantine before testing positive on Wednesday.

Shanghai's health authorities said that all individuals related to the asymptomatic case have already been quarantined.