Train services on the Mandurah line have been cancelled, due to a technical issue.
Transperth tweeted on Monday that they were organising train replacement buses between the Warnbro and Mandurah stations but warned commuters to allow extra travelling time.
Passengers were also reminded that the replacement buses may not connect with bus and train services.
The issue is also expected to cause delays on the Joondalup Line.
For those who require assistance regarding service disruptions or planning your journey, call the Transperth InfoLine on 13 62 13.
Hearing or speech impaired? Call via NRS 133 677 and ask for 13 62 13.