Two men were jailed today for carrying out a "gratuitous" attack on a stranger by setting him alight as he slept on a train.

A judge told Dean Hardy, 20, and Aedan Palmer, 19, that "right-thinking members of the public are understandably appalled by your cowardly and callous actions".

Their victim, Luke Kennedy, 22, suffered severe burns to his lips, ears and cheeks when he was set alight as he travelled home on the 6.50pm Brighton to Littlehampton service in Sussex on December 7 last year.

During their trial, jurors heard that Hardy and Palmer had spent the Sunday afternoon hanging around Lancing, near Worthing, where they had each drunk around 10 cans of Stella.

The school friends had bumped into two younger boys they knew vaguely and the group decided to take the train to nearby Durrington to buy some cannabis. They got on the train at Lancing station without buying tickets just after 7.15pm.

Prosecutors said that from the moment they boarded the rear carriage of the train and sat opposite him, they were taunting and being abusive to Mr Kennedy, who was slumped in his seat fast asleep.

They were described as acting like a "living nightmare" towards Mr Kennedy, before Palmer put a lighter to his "significantly long" beard and set it alight.

CCTV footage from the train showed the group "smiling and laughing" as smoke began to billow from Mr Kennedy's beard before they got off at the next station and fled.

Other passengers still on board the train raised the alarm and Mr Kennedy was taken to Worthing Hospital's A&E department before being transferred to the specialist burns unit at Queen Victoria Hospital in East Grinstead, where he remained for two days.

The attack was widely publicised in the following days and on December 9 Hardy attended the British Transport Police offices in Brighton voluntarily where he was arrested. The other three defendants were arrested the next day.

Hardy was found guilty of inflicting grievous bodily harm following the two-week trial at Chichester Crown Court last month, while Palmer had already pleaded guilty.

The school friends were both cleared of the more serious charge of inflicting grievous bodily harm with intent, while two 14-year-old boys who cannot be named for legal reasons, were found not-guilty on both charges.

Sentencing them at the same court today, Judge Claudia Ackner told Palmer she would take into account the fact that he had pleaded guilty at the first available opportunity, ordering him to serve 16 months in a young offenders' institution.

Hardy, who the court heard has five previous convictions, some of them for violent offences, was told he would serve two years in a young offenders' institution.

Prosecutor Marcus Fletcher told the court that he was convicted of assault occasioning actual bodily harm in June last year after he was involved in an unprovoked group assault on a man who had travelled on a train with them.

One of his party had vomited in the carriage and when the man looked at them to show his disgust he was "attacked and punched and struck" by them, Mr Fletcher said.

During mitigation, Walton Hornsby, representing Hardy, said he was not directly responsible for the attack on Mr Kennedy as it was Palmer who had put the lighter to his beard.

He also pointed out that Hardy handed himself into police, leading to the arrests of the other defendants.

John Greenan, representing Palmer, said he had no relevant previous convictions and had demonstrated "impeccable behaviour" since the incident took place.

He said Palmer, who was recently selected for the England youth sea fishing squad, was deeply remorseful for his actions which he described as a moment of "sheer stupidity" that was not meant to cause Mr Kennedy any real serious harm.

Palmer had described the incident as a "silly joke that went wrong" but the judge said this demonstrated a "severely misguided sense of humour".

She said Mr Kennedy, whose nasal hair, eyebrows and eyelashes were also singed off, remained traumatised by the attack and his ears were permanently disfigured.

Addressing the defendants, she said: "Aedan Palmer and Dean Hardy, your behaviour on the 7th December last year almost defies belief.

"In my view this was a gratuitous attack on a stranger. You abandoned him in a situation where he was unable to look after himself.

"The travelling public are entitled to go about their lawful journeys without being subjected to wanton violence from people like you."

Bespectacled Hardy, of Grace Road, Crawley, and Palmer, of Tower Road, Lancing, did not show any emotion as the sentences were passed.