Rail chaos erupts as NSW train catches fire

Chaos has erupted on Sydney's rail network due to a fire on a freight train near Warwick Farm.

Trains are not running between Fairfield and Liverpool on the T2 Leppington and Inner West Line, and the T5 Cumberland Line, and between Villawood and Liverpool on the T3 Liverpool and Inner West Line, according to an incident update on Transport NSW.

The incident update reports a fire has broken out on a freight train near Warwick Farm, 30km west of the Sydney CBD.

"Replacement buses have been requested but are not yet running," the update states.

"Passengers are advised to delay travel or consider alternative transport and allow plenty of extra travel time."