A 16-year-old boy has been arrested after a man was stabbed at the Notting Hill Carnival, Scotland Yard has said.
The boy was arrested in west London on Tuesday morning on suspicion of assault and is being held in custody, police said.
The victim, a 20-year-old man, was stabbed towards the end of the event on Monday, which otherwise passed off relatively peacefully.
The victim was taken to a central London hospital where his condition was described as serious but stable after he was found with stab wounds to the stomach and hand shortly in Ladbroke Grove, at the junction with Oxford Gardens.
The arrest takes the number of people arrested over the incident to five. The others, three men aged 20 and one aged 21, are being held at various London police stations.
Europe's biggest street festival saw only a small number of isolated incidents amid an unprecedented security operation following the riots in London and other cities earlier this month.
A record number of more than 6,500 police officers patrolled the streets on the carnival's second day, up from 5,500 on Sunday.
Scotland Yard said the latest figure for the total number of arrests during the carnival weekend was 245, up slightly on a total of 243 last year.
Speaking during a visit to the carnival, London mayor Boris Johnson defended the decision to allow the festivities despite worries about street violence following the riots.
He said: "I thought it was very important that we should go ahead. Obviously there was quite a few people who wrote to me saying 'for heaven's sake, scrap it'. But we said, 'no, that would be wrong, because that would be an admission of defeat, if you like, after what happened earlier in the month'."