LONDON - TWO French students found dead in a burning London apartment were subjected to a 'frenzied, brutal and horrific attack', police said on Thursday, admitting they are at a loss to explain the killing.

The bound and battered bodies of Mr Laurent Bonomo and Mr Gabriel Ferez were found in the ground-floor bedsit in New Cross, south-east London, Sunday evening when emergency services were called to the fire and an explosion.

Post-mortem examinations discovered they were dead before the fire took hold and died from multiple stab wounds to the head, neck, torso and back, the man leading the double murder hunt told a news conference.

'I have never seen injuries like this throughout my career.' He added: 'It was a frenzied, brutal and horrific attack... Both appeared to have been bound during this incident.'

As a forensic search of the scene continued, Mr Duthie said the two men, both 23 and biochemists from a university in Clermont-Ferrand, central France, had been on a three-month exchange programme at London's Imperial College.

Described as 'brilliant students' by their French university, they arrived in early May and had been due to return at the end of this month.

'I don't know why these boys were killed or who killed them,' he said, but added he was sure their killer or killers would have been blood-stained afterwards. One line of inquiry is mistaken identity, he added.

He specifically appealed for information about a white man, seen running from the scene shortly after the explosion, which was caused when an unnamed accelerant found throughout the flat rented by Mr Bonomo ignited.

Imperial College said it was shocked and saddened at the deaths.

'Our immediate thoughts are with their families. Laurent and Gabriel had bright futures ahead of them and it is dreadful that their lives should end so soon,' said rector Roy Anderson.

The deaths come amid growing concern about knife crime and gang culture in London, which newly elected Conservative mayor Boris Johnson and Metropolitan Police chief Ian Blair have vowed to tackle.

Police and the Home Office point out that overall knife crime in London is falling. But 17 teenagers have been knifed to death so far this year - already more than half the total number for the last 12 months - raising fears.

The most recent teenaged victim was the 16-year-old brother of a former television soap opera actress, who was stabbed outside a north London bar early Sunday.

The lawyer wife of former prime minister Tony Blair, Cherie Booth, told a parliamentary committee on Tuesday that knife crime was more prevalent than figures suggested, and blades were being carried at a younger age.

On Monday evening, a 28-year-old woman was fatally stabbed by another woman near a burger joint in Peckham, just west of New Cross, in a case that remains under investigation.

Earlier this year, Home Secretary Jacqui Smith - who until recently lived in Peckham, a centre for London's large west African community - said she was too scared to walk the streets at night.

Peckham is the same neighbourhood where a 10-year-old Nigerian schoolboy, Damilola Taylor, died after being stabbed in the leg by teenagers in 2000, in a case that highlighted street crime in Britain's inner cities. -- AFP