Sydney trains have been brought to a standstill by a network-wide communication issue, with no indication when the problem will be fixed.
Trains were stopped at platforms on Wednesday afternoon, with authorities unsure when it would be resolved.
Transport for NSW is advising passengers to consider alternative transport as peak hour approached.
“Trains on the Sydney rail network and intercity lines are stopped at platforms,” Transport for NSW said in a statement shortly after 3.30pm.
“Crews are working to fix the issue as quickly as possible but there is no forecast.
“Passengers already travelling on the rail network are advised to listen to announcements and check information displays for service updates.”