Starting on Wednesday this week, which is tomorrow, all passengers on crowded subway trains in capital Seoul are required to wear a protective face mask as a measure to stem the further spread of COVID-19 outbreak. People without a mask can buy one at the station. The rule comes as Seoul Metropolitan Government announced Monday that it is expanding its “distancing in daily life” measure to include the use of public transport. Once carriages within the train reach over 150% of the recommended quota, and are classed as “congested”, people will be asked to put on masks and further boarding will be restricted. For the busiest lines including the lines 2, 4 and 6, extra trains will run during rush hour and buses will run more frequently.