A technical issue has caused a disruption to the Midland Line trains.
The MerredinLink has stopped at a set of faulty points just north-east of East Perth station and is blocking the line.
Train services have been cancelled between Bassendean and Perth.
Replacement buses are being arranged for commuters.
Normal train operations continue between Midland and Bassendean.
The Fremantle Line is experiencing some delays but is still operational.
Technicians are on site working to fix the problem, but the disruption is likely to last for several hours.