A pervert used his mobile phone to send pornographic images to a woman on a train before masturbating in front of her.

Hassan Ahmed targeted the 33-year-old woman with his Bluetooth device on his phone, as she went to work on the underground between Northwood and Wembley, St Albans Crown Court heard yesterday.

Sandi Evison, prosecuting said 25-year-old Ahmed, of Brightwell Road, Watford, left his victim "petrified" after the incident on the afternoon of Tuesday, July 17.

Miss Evison said the woman, who cannot be named for legal reasons, was using her Bluetooth on a train from Northwood when Ahmed boarded the same train.

"She was clearly targeted." said Miss Evison. "He sent her five pornographic images from his Bluetooth phone and then went to see who had received them. The carriage the young lady was travelling in was not particularly full and she was sat on her own.

"Having sent the images he proceeded to sit diagonally opposite her and masturbate in front of her.

"He was whistling and waving with one arm while trying to get her attention."

Miss Evison added: "She felt petrified and remained in contact with her employer over the phone and when she had the opportunity she changed carriages."

The victim saved the images Ahmed sent under file name "pervert" and contacted staff at the station.

Ahmed, who has no previous convictions, was traced via his Oyster card and CCTV.

He pleaded guilty at a previous hearing to indecent exposure and sending indecent images.

Andrew Copeland, defending, said Ahmed, who works for pre-school football franchise Little Kickers, wanted to apologise to the woman for his behaviour.

Judge John Plumstead said the offences crossed the custody threshold, but agreed with the author of the pre-sentence report that Ahmed could be treated.

For the exposure Ahmed was given a three-year community order to include a sex offenders' treatment programme.

A conditional discharge was imposed for sending indecent images. Ahmed was also ordered to pay his victim £750 compensation and prosecution costs of £400 were awarded.

Judge Plumstead said: "No money can repair the confidence that's been damaged. The money is a token, so she can do what ever she likes with it, so she can benefit from the shock and disgust she felt from what you did.

"You have no right to take out your frustration on others, do you understand that?"

"Yes," Ahmed replied.

Ahmed was not banned from working with children but must sign the sex offenders register for five years.