A teenager who fell to his death from a block of flats was trying to escape a gang of masked youths by climbing down the outside of the building, police said today.
Witnesses said 16-year-old Ahmed Benyermak may have feared he was about to be attacked with a knife by the hooded bicycle-riding gang.
Scotland Yard said the boy climbed down six floors on the outside of the tower block in Hackney, east London.
But when he reached the seventh floor his path was blocked by a metal grille and he apparently lost his footing and fell.
Neighbours said Ahmed was with friends when he was chased by another gang, some of whom were carrying knives.
They escaped into the Trelawney Estate and ended up gathering on a balcony on the 13th floor of the Paragon Road tower block.
Police were probing whether shouting between Ahmed's group and their pursuers led to his fateful decision to climb down the building.
Police and paramedics found Ahmed lying on the ground with fatal injuries shortly before 4pm yesterday. He died at the scene.
The boy's headmaster Richard Brown, of Hackney Free and Parochial Secondary School, said Ahmed was due to collect his GCSE results today.
Mr Brown said the boy's family are "shocked and devastated" by the death, which he feared was gang related.
He said: "We expected today to be about GCSE results and what you then find is one of the youngsters who has worked very hard for their GCSEs has been the victim of this tragedy so people are very shocked and upset.
"Ahmed's only been here a year. The great achievement is he achieved 9 GCSEs.
"I've spoken to his family this morning and they are most proud of the fact that he got a C in maths and a C in science. He also got two other C grades.
"Family members came in and found out about his results but not his parents because they were too upset.
"The family is shocked and devastated. His tutor said to me he never would have expected Ahmed to be involved in this sort of incident.
"Within the context of the school, there is almost no issue to do with gangs because we try and create the Hackney Free community.
"Clearly there are a lot of issues going on locally and nationally but they hardly impact on the school at all.
"But suddenly we have had this dreadful tragedy, possibly as a result of gang activity."
One neighbour said: "I've heard that he saw a gang chasing someone else and he thought they were carrying knives.
"Apparently when he saw the knives he started to run towards the flats and the gang chased him."
Police forensic experts were studying the scene of the tragedy where floral tributes had been laid with tributes to Ahmed.
Detective Chief Inspector Ian Stevenson said: "This is a tragic and unnecessary death.
"The victim was with a group of friends on the 13th floor of a tower block when they became concerned about another group of youths cycling towards the tower block.
"This caused the victim and his friends to leave the area. The victim was separated from his friends.
"He climbed onto the outside of the tower block via an open balcony and then climbed down several floors trying to escape.
"He reached the seventh floor when he could no longer carry on. After this point he fell to his death.
"The other group involved are described as black male youths. Some were wearing hooded tops others were wearing bandanas and were riding pedal cycles.
"I am appealing to anyone who witnessed the victim fall from the tower block and anyone who witnessed events prior to him fall to please contact police."
Anyone with information is asked to call Crimestoppers on 0800 555 111.