Forty-nine arrests have been made by Metropolitan Police at Children's Day at the Notting Hill Carnival.
Police stayed in the area as revellers began leaving the street party after dark.
Eighteen of the arrests were for drug-related offences; six were for suspected robberies; five were for criminal damage; five were public order offences and seven were for assaults, including two for grievous bodily harm.
A Metropolitan Police spokesman said the most serious incident took place at around 5.15pm in Golbourne Gardens in Kensington, west London, when a 14-year-old boy was slashed with a sharp object.
Thousands of revellers celebrated Children's Day at Sunday's Notting Hill Carnival - a street party that goes back almost 50 years. More than a million people are expected over the two-day event.
ITV News reporter Toby Sadler reports: