Trains on a major route may be delayed or cancelled this morning after overhead electric wires were damaged, says National Rail Enquiries.
Travellers using the Preston and Manchester Piccadilly / Wigan North Western routes have been warned to expect disruption.
Affected train companies include Northern, TransPennine Express and Virgin Trains.
A Network Rail spokesman said in a statement: "Damage to the overhead electric wires between Preston and Manchester Piccadilly / Wigan North Western is causing disruption to journeys between these stations.
"Trains may be cancelled, delayed by up to 30 minutes or revised.
"A normal service is expected to resume by 07:30."
Travellers are advised to check before they travel.
An update at 7.33am advised customers that following the damage to the overhead electric wires, trains are now able to run normally.