A flight attendant wearing a face mask to prevent the spread of coronavirus disease (COVID-19) takes body temperature measurements of passengers with a thermometer on a Shanghai Airlines flight in Shanghai, China March 25, 2020. REUTERS/Aly Song

SHANGHAI (Reuters) - The eastern Chinese city of Shanghai will make all incoming travellers undergo 14 days of quarantine and observation from Thursday in a bid to prevent coronavirus transmission, the local government announced.

Shanghai had previously required travellers to go into quarantine only if they had visited 24 badly hit countries in the two weeks before their arrival in the city.

The city reported 109 confirmed and active coronavirus cases imported from overseas by the end of Wednesday, up 18 compared to the previous day. It said 39 were from Britain, and 27 from the United States.