The number of teenagers murdered in London this year reached 27 yesterday, higher than the total for the whole of 2007 with three months of the year remaining.

Scotland Yard is now braced for the death toll to exceed 30, more than double the figure five years ago.

The latest victim was Craig Marshall, 19, from Acton, West London, who was stabbed in what locals said was an argument over payment for a drug deal.

Mr Marshall stumbled 50 yards from where he was attacked outside a tower block into Acton police station at around 11pm on Thursday night. He was taken to hospital by ambulance, but despite emergency surgery died at 8am the next morning.

Residents of Rufford Tower, the block where Mr Marshall was attacked, said the victim had had an argument with two men, believed to be of Sri Lankan origin. Police have arrested two suspects, aged 20 and 21.

Nasren Azad, 37, said: “He wanted £20 from them and it was that which started the argument. It’s only £20 and now this happens. We are so shocked.

“They had the argument after the boy came to the door. When he rang the entryphone the others, the ones who have been arrested, came down and that’s when it happened.

“The boy said to them to give him the £20, but they said they didn’t want to give it to him and told him ‘What do you want to do about it?’ The police took the whole family into the van after the stabbing.”

A friend of the dead youth claimed that the argument broke out over a cannabis deal. Steve Mingard, 19, said: “All this happened over weed. It’s pathetic. They wanted some weed and it was a bit under the required amount and they just stabbed him. He wasn’t a bad guy. It’s just stupid.

“Craig was a really good person. He had just finished a painting and decorating apprenticeship, he wasn’t a troublemaker.”

Gary Jackman, 17, another friend of Mr Marshall, said: “I spoke to his brother this morning and he was just saying that he had been stabbed twice. I think it was in the stomach.

“He was really sunny, he would take everything and make it into a joke. If you were going through something bad, like with a girlfriend, he would advise you what to do.

“The other day he was saying he wanted to go to college and do something with his life and get out of his estate. He wanted to improve his life. I’ve been up all night and I’m just speechless. I just thought, ‘It’s not him, it’s not him’.”

Last year, Sir Ian Blair, the Metropolitan Police Commissioner, said that the number of teenage murders in London was “completely unacceptable”.

The Met is running an anti-knife crime initiative, Operation Blunt2, in which thousands of weapons have been seized. The Home Office is also diverting resources to tackling gang and youth violence. But the number of murders has continued to rise.

In 2003, 15 teenagers were victims of homicide in the capital and the figure remained around the same level until 2007, when it rose to 26.

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