Two teenagers found guilty of stabbing a vulnerable asylum seeker to death in Edgware have lost an appeal against their sentence.

The boys, aged 14 and 15 at the time of the attack in July last year, were jailed for eight years in April at St Albans Crown Court after being convicted of killing 24-year-old Abdul Gwalugano. Mr Gwalugano was a schizophrenic asylum seeker who regularly begged for money around the Stonegrove estate.

The boys, who cannot be named because of their ages, challenged their convictions on the grounds that the original trial judge should have ruled there was no case to answer' at the close of the prosecution case.

But sitting at the Court of Appeal last Thursday, Lord Justice Hughes ruled the judge had been entirely right' to allow the case to proceed on the basis of the prosecution evidence. He ruled there was no basis' for concluding that the convictions were unsafe.

Mr Gwalugano died from a single stab wound on July 26 last year following a heated argument in King's Drive, Edgware, near his ground-floor flat in Salisbury Court, Lacey Drive. The prosecution was unable to pinpoint which boy had stabbed him, but suggested that the older of the two was probably the killer.

They were prosecuted on the basis of joint enterprise' - the legal principle that they were both involved in the crime as each knew that the other had murder in mind.

During the trial both boys claimed the other was the killer.

Rejecting their appeal, Lord Hughes said there was no eyewitness account of Mr Gwalugano's death available to the prosecution, although at least 13 people had seen the argument.

It was an unsurprising feature of modern urban life' that none of the witnesses had come forward, he added.