Starting from Tuesday, passengers in Beijing will be asked to show their green health codes before getting on buses and subway stations operating near the locked down and controlled zones, said Rong Jun, spokesman of the city's transport commission, at a news conference on Monday.

He said due to the complicated epidemic situation in the city, especially the recently reported cluster involving a bus station that has resulted in six confirmed cases, the transport authority will strengthen control measures for the city's traffic system.

"The staff will ask passengers who fail to show green health codes to leave those public transportation locations for safety," he said. "However, seniors and children who don't have smartphones and don't know how to show the code still can get on those buses and subways."

The new regulations will involve 190 bus lines and 54 subway stations.

The commission is working on upgrading the bus and subway ticket system which will combine information on passengers' transit cards and health codes.

It's expected to be completed by the end of May. By then, it will be more convenient for passengers to get on buses and subways.