Police are appealing for witnesses after a 35-year-old woman was punched and spat at on a train.

The woman was travelling between Balham and Streatham Common stations when another passenger began talking loudly on his phone and using offensive language.

She asked him to be quiet but he became aggressive and attacked her as she tried to leave the train at Streatham Common.

Police want to speak to a man (pictured) who they believe may have information about what happened.

PC Neil Allison, who is investigating the incident, said: "This was an unprovoked attack on a woman who had simply asked the man to tone down his language.

"The carriage was very busy and I’d like to hear from anyone who knows the man responsible, or who saw what happened, as they may be able to assist our investigation."