A landslide has derailed a train causing serious disruption to rail passengers.
Network Rail said one carriage of the 10.59am Bognor to London Victoria service left the tracks near Redhill, Surrey, at about 12.18pm.
A spokeswoman said there were no reports of serious injuries, but other train services will be severely disrupted.
The incident took place at Merstham Tunnel, several miles north of Redhill. The train is operated by Southern.
She said: "There was a landslide. One carriage of the train came off the track but remained upright. We have no reports of any serious injuries.
"There is going to be serious disruption on that line for at least the rest of the day."
A British Transport Police spokesman said the driver reported no passenger injuries.
He said: "It was the front carriage of the train that derailed due to a landslip. But the entire train remains upright and according to the driver there are no injuries.
"Police and emergency services are soon to arrive on the scene. It was a Southern train. People travelling on the Brighton to Victoria line should expect severe delays."
He added that the incident took place between Merstham and Coulsdon South stations.
