A 21-year-old woman had her phone snatched from her hand while sitting on a train at Harpenden Station.

The robbery took place on Tuesday, August 28, as the woman was travelling to Luton with her family just before 11.30am.

British Transport Police are appealing for witnesses and have released a CCTV image of a man they wish to speak to in connection with the incident.

Detective Constable Graeme Knox said: "The woman had boarded the 20.44 Brighton to Bedford service with her family shortly before 11.30am.

"A short while later, a large group of people boarded the train at St Albans and sat in the same carriage in the seat behind the woman and her family.

"At Harpenden, the group all got up, with one man reaching over and grabbing the phone, a white iPhone 4, out of the woman’s hand, before exiting the train."

Police would like to identify and speak to the man in the CCTV image, as they believe he can help them with their enquiries.

DC Knox continued: "We’ve followed a number of local leads to try and find out who this man is and want to hear from anyone who recognises him."

Anyone with information about the incident is asked to contact British Transport Police on 0800 40 50 40 quoting reference B6/LNA of 17/09/12 or call Crimestoppers on 0800 555 111.

Police are also encouraging travellers to be alert when using electrical items such as mobile phones or mp3 players in public to help lower their chances of becoming a victim of crime.

DC Knox added: "Smartphones are very desirable for thieves, mainly because of their high sell-on value.

"Typically they will target passengers who have their phones or other electronic items out in the open, because potential victims are more likely to be distracted, making it easier for them to snatch the items.

"We aren’t asking people to stop using their mobile phones, but to be more aware of their surroundings when using expensive items in public as this will help reduce the risk of being targeted."