A man was knocked unconscious and suffered a broken leg in a "particularly nasty" assault on a train.

The victim was attacked after asking a man to stop behaving anti-socially on the delayed 7.59pm service from London Bridge to Gravesend last night.

The train terminated at Dartford, and the victim was taken to hospital for treatment.

Police are now appealing for witnesses to come forward.

DS Allan McTaggart said: "I'd appeal to anyone who witnessed this incident or believes they may have information to get in touch with us as soon as possible.

"This was a particularly nasty assault and one we are taking extremely seriously."

Anyone who witnessed the incident is asked to contact British Transport Police by texting 61016 or calling 0800 40 50 40 quoting reference 26 of 17/11/18.