Several people were injured as violence sparked at Notting Hill Carnival
Three men were stabbed and two police officers were injured in a series of violent clashes at the Notting Hill carnival on Monday evening.
The Metropolitan Police imposed Section 60 public order measures, giving officers powers to stop and search, in response to the stabbings.
The police officers were assaulted during an attempted arrest of a man suspected of drug dealing.
The Met said 252 arrests were made over the two-day street festival.
Of those, eight people were arrested after disorder at the corner of Colville Terrace and Colville Gardens, Notting Hill, in which a 29-year-old man received a serious stab wound. He was taken to hospital and remains stable.
In addition, a man was arrested over the stabbing of an 18-year-old man in Southam Street, Kensington, and one man was held on suspicion of attempted murder following another stabbing of a 25-year-old.
Police earlier mingled happily with revellers enjoying
There were 76 arrests over suspected drug offences, 43 for public disorder and 23 for possession of offensive weapons.
The number of arrests was down on last year, when 301 people were detained, and 2012 when 278 people were held.
Met Police commissioner Sir Bernard Hogan-Howe said: "Although early indications are that reported crime is down at this year's Notting Hill Carnival, I am concerned by the number of stabbings over the weekend.
"Stabbings are up on last year, and in some cases these are just centimetres from being a murder.
"Each will be thoroughly investigated and we will do everything possible to ensure those who brought trouble to Carnival are placed before the courts."
A 33-year-old male police officer and his 35-year-old female colleague were taken to hospital after being assaulted at the junction of Lancaster Road and St Luke's Road at 15:15 BST.
The man's condition is not life-threatening but it is understood he was unconscious at one stage following injuries to his head and torso. His colleague sustained torso injuries but was discharged from hospital.
Sir Bernard said: "Two of my officers were injured during an arrest yesterday and this shows the risks they must take.
"I would like to thank all the officers and support staff for their hard work in the most difficult of weather conditions.
"Their commitment is a major factor in ensuring the Carnival is a safe and enjoyable event for the vast majority of those attending."
The decision to use the Section 60 and Section 60AA orders was taken by the commander in charge of policing on Monday evening.
It was in use from 19:00 until 02:00 on Tuesday.
Section 60 of the Criminal Justice and Public Order Act 1994 allows senior police officers to authorise constables to stop and search people in a specific area, either where a serious public order problem is likely to arise or has taken place, or for offensive weapons or dangerous instruments.
Section 60AA gives police powers to order the removal of disguises where section 60 has been invoked.
The heavy rain failed to dampen the spirits of most of the carnival revellers
Scotland Yard said on Monday night the measure was taken "in response to incidents of violence, and intelligence received, which have taken place within a short period of time in the last few hours".
Chief Constable Alex Marshall, chief executive of the College of Policing, told BBC London 94.9: "From what I understand from what the Met did last night, it's exactly in line with these new guidelines.
"They did it for a very limited period of time, it used to be 24 hours they did it for a few hours and they got the chief officer to authorise it and not the officer on the ground."
The Metropolitan Police deployed 7,000 officers for Monday's event, 1,000 more than on Sunday.
The annual Notting Hill carnival is thought to be Europe's largest street party and represents one of the biggest operational challenges in the force's calendar.