HONG KONG — Passengers on Hong Kong's metro system faced disruption for the second time this month on Thursday (Oct 25) , when trains were delayed on two rail lines.

Train services for the Tseung Kwan O Line and Kwun Tong Line were gradually resuming after a short suspension and delay, according to rail operator MTR announcements early Thursday morning.

Train services for Po Lam station were earlier suspended due to power supply problems, the operator announced at about 7am. Shuttle buses were arranged for affected passengers.

Services for other stations along the Tseung Kwan O Line were also delayed as a result.

At the same time, services on the Kwun Tong Line were delayed due to signal problems. Train frequency was reduced to every 10 minutes.

The MTR experienced its worst breakdown ever on October 16, when the signalling system on four major lines – Island, Tsuen Wan, Kwun Tong and Tseung Kwan O – stopped working shortly before rush hour, causing chaos at stations and inconveniencing thousands of commuters.

The glitch just over a week ago delayed trains and extended journeys by as much as 40 minutes.

The following day, MTR Corporation's chief engineer said the 6-hour disruption was caused by rogue computers operating without orders. Initial investigations have found an uncontrolled transfer of large amounts of information between computers was responsible for the breakdown.

However, the chief engineer, Mr Tony Lee Kar-yun, said he still did not know why the system failure had happened. SOUTH CHINA MORNING POST