The father of a teenager stabbed to death in a fight in south London has said knife crime is out of control.
Police found two knives and a claw hammer at the scene
Alex Mulumba Kamondo, 15, was with friends when they were surrounded by another group in Black Prince Road, Lambeth, on Thursday night.
A row broke out between the two groups and Alex was stabbed in the chest.
His grieving father Kamondo Mulumbu visited the murder scene on Friday. He said: "Alex was a good boy, he had nothing at all to do with knives."
He added: "Knives are out of control. Most young people are walking around (with them)."
Mr Mulumbu said his other son had called him to say Alex had been stabbed and was in hospital.
Within 10 minutes of arriving at the hospital, doctors told him they had done their best but "my son is no more in life".
Alex was from Zaire originally and lived in the Kennington area, near the spot where he was murdered.
Police said they wanted to trace 10 black youths, in their teens, who were wearing dark clothing.
Det Supt Richard Heselden said after the row between the two groups, the larger group left the scene and returned armed with various weapons including baseball bats and hockey sticks.
At least two knives and a claw hammer were recovered from the scene and forensic tests are being carried out to determine whether they are linked.
Police said the motive for the attack is unknown.
"You have a 15-year-old who had everything to live for who is now no longer with us," said Mr Heselden.
"It's another tragic incident and I would urge people not to carry knives."
Police are conducting a forensic examination of the area and carrying out house-to-house inquiries.
Officers are also checking to see if the attack was captured on CCTV.
"It was a warm summer evening and we are sure the streets would have been busy at the time of the murder," Mr Heselden added.
A mobile police station will be set up to help with the inquiry and patrols will be stepped up to offer reassurance to the public.