A 14-year-old girl faces questioning after she was arrested over the fatal stabbing of a promising teenage footballer.
Junior Nkwelle, 15, was killed outside a block of flats in Brixton, south London, in an attack which police do not believe is gang-related.
Officers were called to a disturbance on the Loughborough Estate on Thursday night and found the boy with serious stab wounds.
He was pronounced dead at the scene. A post-mortem examination began on Friday.
A 14-year-old girl was arrested on suspicion of murder and remains in custody.
Locals expressed shock over the death as they gathered to look at flowers left at the address.
One card on a tribute said: "Dear Junior, You was a good friend, a great footballer and a great person. Justice will happen. I promise!"
Another said: "If football be the food of love 'Play on'. RIP young fella."
Solomon Smith, 27, a youth support worker at Marcus Lipton Youth Centre a few yards from the scene, said youngsters in the area had suggested he might have been killed in a fight over a girl.
He said: "He was one of our locals, and had been coming here for about two years.
"He was a very good footballer. When he came in, he always played football indoors here.
"He was a very quiet guy, you wouldn't think anything like this would happen to him."
Faith Marriott, 30, who lives locally, said: "He was a friendly boy, he wasn't in a gang."
Mrs Marriott's brother David, who helps run local youth project Lambeth Tigers, said: "He's been coming to us for about four months and coached younger boys at football. He was a brilliant kid, only 15, but a good role model for this community.
"He was always smiling, an asset - to lose somebody like this is devastating."
Detective Chief Inspector Charles King said: "We would appeal for anyone who has any information, or witnesses to come forward as soon as possible."
:: Anyone with information can call detectives on 020 8721 4054 or Crimestoppers anonymously on 0800 555 111.