Housny Bouliaz, 18,was convicted of kidnapping and sexual assault and jailed for three and a half years

A failed asylum seeker who tried to rape a young woman in a car park was only stopped after three have-a-go heroes spotted his vile attack.

Moroccan Housny Bouliaz, 18, who has a string of convictions, pounced when he saw a lone woman walking home after a night out and dragged her into a dark car park in Canterbury, Kent.

However, he was halted from carrying out his vile crime when friends Edd Withers, Charlie Vanstone and Sam saw him grab the woman off the street.

Homeless Bouliaz, who had not been deported after his asylum application was rejected, fled the scene and evaded police.

He was only caught when he and two other failed asylum seekers took part in the mugging of a student in March, four months after the sex attack.

Bouliaz was convicted of kidnapping and sexual assault after a trial at Canterbury Crown Court and was jailed for three and a half years.

Judge Heather Norton told him: 'You are well-practised and predatory and are willing to take risks to meet your offending needs.

'You are a person who preys on vulnerable people in order to commit these offences and get funds to sustain your drug habit.

'It is likely at the end of your sentence you will be deported - but that's not a matter for me.'

Friends Sam Eagleson, Edd Withers (left) and Charlie Vanstone (right) stopped Bouliaz when they saw him grab the woman off the street

Describing the sex attack, Mr Withers, 30, said he was working for his cake delivery firm and was with Mr Vanstone, 23, and Mr Eagleson, 23, when they saw Bouliaz and the girl.

He said: 'I only just saw it out the corner of my eye, but it just didn't look right.

'We went over there and he was literally in the process of assaulting the young woman.

'He was lying on top of her and no one knows really what might have happened.

'Charlie started to film the guy and then chased after him when he ran away.

'The girl was very shaken up by it, we were just in the right place at the right time.

'It's frightening, but I've been in Canterbury for ten years now and nothing like this has ever happened to anyone I know.'

Mr Vanstone added: 'We were pretty angry about what we'd seen.

At Canterbury Crown Court, Judge Heather Norton told Bouliaz: 'You are well-practised and predatory'

'Before he ran off, Bouliaz was denying what he was up to, but it was clear that he was about to have sex with the victim.

'Canterbury is a pretty loving city, but obviously it can attract the wrong people.'

John Barker, defending, said his client made his way to Europe after he claimed when aged eight his mother threw hot oil over him, leaving him permanently scarred.

Boulaiz has convictions which began in 2013, including thefts of bikes, robbery, attempted robbery and making threats to kill after attacking a man.

He was also jailed for five weeks for his part in the robbery of Canterbury University student Ting Yo Lin as he walked home from a pub.

Boulaiz, fellow Moroccan Yassine Hamadoni, 20, and Algerian Adil Nazar, 27, used a ploy known as 'hugger mugging' - where they pretend to befriend their victim before robbing him of his £600 phone.

Hamadoni was on bail at the time and had previous convictions for burglary last October and 10 shoplifting offences dating back to 2013.

He was also convicted of a sex offence in London last year and was sentenced to two years behind bars.

Kitchen porter Nazir, who is appealing his asylum rejection, has convictions for causing criminal damage and shoplifting in 2014 and was jailed for 20 months.