MAHB said passenger recovery procedures were immediately activated, with airport response teams deployed to assist those on board and transfer them to the terminal.

In a statement, it said one of the aerotrains resumed service at 9.27pm, while rectification work was ongoing on the second unit at the time of writing.

MAHB said alternative transport arrangements were immediately activated to ensure continuous passenger movement between the terminal and satellite building.

“KLIA is conducting a thorough investigation to determine the root cause of the incident,” it said.

“We regret the inconvenience caused and appreciate the patience and understanding of all passengers as recovery work progresses.”

This is the second power-related disruption to the aerotrain service in recent months, following a similar incident on Sept 4 that affected one of the trains.

The aerotrain had undergone a scheduled two-week overnight maintenance period between Aug 18 and Aug 31.