A train has broken down and blocked the line between Preston and Euxton Balshaw Lane.
It means services running through these stations will be diverted, as trains heading to Preston are unable to call at the Euxton station.
Northern Rail said disruption is expected until 10.30am.
Passengers at Euxton are being advised to travel to Wigan North Western for onward connection.
Passengers heading to Euxton Balshaw Lane are advised to change at Preston for connecting services to Euxton.
If you've been delayed by 30 minutes or more, hold on to your tickets and claim compensation by visiting northernrailway.co.uk/delayrepay