BEIJING - No need to swipe a card or scan a QR code. A Beijing subway line now allows passengers to enter and exit "empty-handed" by scanning the palms of their hands.

A pilot program launched on Sunday to apply the new technology on the Daxing Airport Express, which links the Beijing Daxing International Airport, said the Beijing Municipal Commission of Transport.

Passengers can show their palms to pass ticket gates at stops along the line after inputting their palm information at the station's ticket machines and authorizing the use via WeChat, a popular messaging app in China. Fees are automatically deducted after exit.

The ticket gates recognize the user's palm print and veins without contact, said the commission. It can allow passengers to take subway trains if they do not have cash when their smartphones run out of battery.

The commission said data masking and encryption technologies have been applied to protect the user's information.