Police officers have been attacked while attempting to disperse crowds at an illegal party for the second night in a row.
The Met Police said objects were thrown at officers at an “unlicensed music event” in Notting Hill, west London, in the early hours of Friday.
A witness said there were “about 150-200 people” present with violence breaking out from about midnight.
It comes after “appalling scenes” of violence at a street party in Brixton.
Malcolm, who has lived in the area for 10 years, told the BBC “about 150-200 people” had started to gather at the corner of Portobello Road and Blenheim Crescent from about 21:00 BST.
“After midnight it seemed to switch into more violent behaviour,” he said.
He added that it had been “pretty terrible round here” for the last few nights with “anti-social behaviour, alcohol, drugs and a huge amount of violence and disruption”.
Kensington and Chelsea Police tweeted that objects had been thrown at officers dispersing the crowd at the event near Colville Gardens.
“Violence will not be tolerated and units are responding appropriately,” the force said.
The Met later said most people had dispersed from the area by 02:00 and there were no confirmed reports of serious injuries.
Meanwhile, officers also attended another unlicensed music event at Streatham Common on Thursday evening.
The force tweeted that officers had “engaged with a large number of those in attendance and the crowd has now almost entirely dispersed”.
On Thursday evening, Scotland Yard said it was undertaking an “enhanced policing operation” across the capital to ensure there was an “effective and prompt response to any reports or disorder”.
Commander Bas Javid said the move was “in direct response to concerns expressed by our communities, many of whom were scared and shocked by the events taking place outside their homes.”
Extra police officers in protective gear were dispatched following “appalling scenes” of violence at a street party in Brixton on Wednesday.
Scotland Yard said it was targeting further unlicensed music events and block parties around the city after 22 officers were injured on the Angell Town estate.
Footage on social media showed police vehicles smashed and officers pelted with bottles during clashes with a large crowd, with Downing Street condemning the scenes as “appalling” and Home Secretary Priti Patel calling the incident “utterly vile”.