A man has been stabbed to death on a London Waterloo-bound South Western train.

Police were called at 1.15pm on Friday to Horsley station in Surrey after the man was knifed on a train travelling between Guildford and Waterloo.

The "incredibly frightening" attack took place in front of shocked passengers with one witness claiming there was "blood everywhere".

Paramedics battled to save the victim but he was pronounced dead at the scene. Police later said he was a 51-year-old man who was travelling with his 14-year-old son.

The male suspect, who is still at large, fled from the train at Clandon, the station before Horsley.

One passenger, who asked not be named, told the Daily Mail there was "blood everywhere in the carriage".

Another person wrote on the social media that the response of the train staff was "incredible".

They wrote: "I was on this train, how those guards and especially that train driver went into action was nothing short of incredible. Not sure if it's appropriate to say thank you, but I do hope everyone is ok after today's event."

A British Transport Police (BTP) spokeswoman confirmed no arrests had been made.

A number of police officers remained in the Clandon area into the evening and were attempting to identify and trace the suspect.

Detective Superintendent Gary Richardson, from BTP, said: “This was a shocking and violent attack which took place on-board a train in broad daylight.

“Officers from BTP are with the family and have deployed a specially trained family liaison officer to support them through this difficult time.

“We know that this was an incredibly frightening incident for passengers travelling on the train. We believe that the suspect and victim boarded the train at London Road at 1.01pm and we would encourage who was on this train to come forward regardless of whether or not they think they can help our investigation. We believe the suspect departed the train at Clandon station.

“Passengers and members of the public can expect to see an increased presence by BTP and Surrey Police officers at Horsley and Clandon as our enquiries continue.

“We would advise anyone in the local area who sees anyone they think maybe the suspect to contact 999 immediately.”

Matt Phelps, 35, who works at a business in West Clandon, said police officers provided a description of the man they were hunting - a man with a beard and short hair, who was "not dressed for the weather" in a T-shirt and tracksuit bottoms, and strikingly bright white trainers.

He said: "There were also three helicopters circling overhead when we locked up and went home.

"It was a bit alarming when someone I worked with put two and two together and we realised who the police were looking for.

"To think there was someone like that potentially hiding around the corner somewhere certainly made us want to pack up and go home quicker than usual."

Trains between Guilford and Effingham Junction were blocked after the incident, with disruption expected in the area until at least 9pm.

Anyone who witnessed the incident or with any information should contact BTP by sending a text to 61016 or by calling 0800 40 50 40 – quoting reference 210 of 04/01/19. Or you can ring Crimestoppers anonymously on 0800 555 111.