Britain’s knife crime surge claimed another victim when a 17-year-old was stabbed to death outside a block of flats in west London.

Police arrived just after 10.30pm on Friday after reports that a teenager had been stabbed following an attack near a block of flats in Isleworth.

Paramedics battled in vain to save the teenager, who was pronounced dead at the scene, a short walk from Syon House, the family home of the Duke of Northumberland.

A murder investigation has been launched and no arrests have yet been made.

Neighbours have spoken of their horror at the scene that confronted them moments after the youth was attacked and left dying in the street.

One couple said they heard shouting and looked out of their flat to see the teenager being assaulted by two people.

The pair, neither of whom wished to be named, said one of the attackers had his face covered.

The husband, a 33-year-old engineer, said: "It was one guy who was massive with, like, a mask on his face and another small guy. They were kicking him (the victim), but it was dark so it was hard to see exactly what was happening."

By the time the couple went downstairs to the scene they said the two attackers had left.