Commuter chaos has broken out in Perth’s south-east after an incident on the Armadale train line.

Perth Transport Authority issued an alert just before 6.30am warning of the line’s cancellation “effective immediately” after a shopping trolley was left on the tracks.

“Trains on the Armadale Line are cancelled between Cannington and Armadale due to an incident,” a PTA spokesperson said.

“The incident was due to a shopping trolley left on the tracks near Fremantle Road in Gosnells on the Armadale Line.

“Crews have since removed the trolley with services set to resume shortly.

“Delays are expected as services will not be running to their regular timetable.

“We thank you for your patience as we work to restore services as quickly as possible.”

Train replacement buses are running between Cannington and Armadale, with travellers told to allow extra time.

Commuters are encouraged to check bus routes and the PTA journey planner for alternative ways to travel.