London riots: Looting and violence continues
Shops were looted and youths clashed with police in Enfield
Police have condemned a wave of "copycat criminal activity" across London in a second night of looting and disorder following riots in Tottenham.
Officers had been attacked and a number of police vehicles had been damaged, the Metropolitan Police said.
A Footlocker shop in Brixton, south London, was set on fire while other nearby stores were looted.
Three officers were hurt when a vehicle hit them as they tried to make an arrest in Waltham Forest, east London.
Disorder has also been reported in Enfield, Walthamstow and other parts of the capital.
Clashes broke out in Enfield, north London, on Sunday evening where shop windows were smashed and a police car damaged.
Several arrests were made but police said the situation there had now been contained.
There have been reports of a gang of up to 200 youths looting shops and charging police in Coldharbour Lane and the High Street in Brixton, south London.
The Met said it had dealt with several incidents of "copycat criminal activity" across the city.
A Footlocker store was one of several shops looted in Brixton
Three officers injured after being hit by a vehicle in Chingford Mount, Waltham Forest, at about 00:45 BST
More than 30 youths vandalising and looting a number of shops in Walthamstow and Waltham Forest
Vandalism carried out by about 50 youths in Oxford Circus, central London
A police vehicle being attacked in Islington, north London
A Tesco store in Ponders End being attacked and items stolen
Journalist Padraic O'Brien told BBC 5 live he had witnessed widespread looting in Brixton.
He said: "They smashed a William Hill, they set bins on fire, etc...
"And now what we're seeing as the night progresses is that replicated, sort of flashpoints all along Brixton High Street.
"I've seen a Vodafone looted, I've seen a Footlocker looted and set on fire, I've seen Marks & Spencers attacked.
"I've seen a striking number of mobile phone stockists that have been targeted.
"I'm standing outside Halfords on the other side of the road and they've just smashed through the doors of Halfords. They're taking bikes out the front entrance.
"I have to say, what really struck me was the small number of police officers that there actually seem to be on Brixton High Street responding to this."
Rhoda Dakar also saw the trouble in Brixton.
He said: "I saw smoke coming from one side of the railway bridge. The was a strong toxic smell in the air.
"Youths were looting and running with poles - at that point I chose to leave and go home.
"You could tell youths were just out there waiting for something to happen."
Met Police Commander Christine Jones said: "This is a challenging situation with small pockets of violence, looting and disorder breaking out in a number of boroughs.
'In harm's way'
"We have deployed units across London and continue to move quickly to deal with any reports of criminality as soon as possible.
"Officers are once again putting themselves in harm's way to arrest those responsible and prevent further crimes. I am proud of their dedication and bravery.
"I, along with the vast majority of Londoners, condemn this mindless criminality. It serves no purpose and only results in the destruction people's livelihoods and communities."
London Fire Brigade said it had been called to a number of fires in Enfield, Brixton and Walthamstow, including a fire at a shop on Brixton Road where 30 firefighters were tackling the flames.
The disorder follows rioting in Tottenham which broke out on Saturday night and continued into Sunday morning.
A peaceful protest over the fatal shooting by police on Thursday of 29-year-old Mark Duggan descended into violence later in the evening.
The unrest spread into nearby Wood Green and Tottenham Hale. Shops were attacked and looted, 26 police officers and three others were injured and buildings and vehicles were set alight.
Parts of Tottenham are still cordoned off, as officers and forensic specialists continue to examine the riot scene.
As well as Mr Duggan, a police officer was also shot in Thursday's incident, which happened in what was called a "pre-planned" event, under Operation Trident, which investigates gun crime in the African and Caribbean communities.
Police had stopped a minicab which Mr Duggan had been travelling in.