British Prime Minister David Cameron has pledged to restore order after three days of riots, looting and arson in London spread to other cities.
Rioters fought with police in the capital, in Birmingham, Liverpool, Manchester, Leeds and Bristol on Monday in the country's worst unrest in decades.
Mr Cameron broke off his holiday in Italy to return home to chair a meeting of the government's crisis committee and said the Metropolitan Police will have 10,000 more officers on the streets of London for an expected fourth night of trouble on Tuesday.
The Prime Minister condemned the "sickening scenes" of violence, saying it was "criminality, pure and simple and has to be confronted and defeated."
"People should be in no doubt that we will do everything necessary to restore order to Britain's streets and to make them safe for the law-abiding."
Parliament will be recalled for a day on Thursday to allow Mr Cameron to make a statement about recent events.
The violence began on Saturday in Tottenham, north London, when a peaceful protest over the police shooting of suspect Mark Duggan last Thursday was followed by outbreaks of looting and arson.
Neighbourhoods face a massive clean-up of smashed glass, bricks, bottles and gutted buildings as police reinforcements reclaimed the streets from the youths who used social media to coordinate the unrest.
Politicians and police blamed the riots on criminals and opportunistic hooligans. But residents in affected areas of London and some commentators attributed the unrest to local tensions and anger over economic hardship in a city where the gap between the haves and have-nots is growing.
Monday's rioting started with missiles being hurled at police in the north-east suburb of Hackney. The violence then spread to areas including Clapham Junction, Woolwich, Ealing, Peckham, Lewisham, Brixton and Croydon.
Laura Harris, a New Zealander living in Clapham Junction told Radio New Zealand she got off the train on Monday to find dozens of riot police, a helicopter overhead and crowds smashing shop windows. She took refuge in her second floor flat.
Alan McCabe, a landlord in Croydon, told the BBC the rioters are ruining the lives of innocent people.
"They don't care - I've never seen such a disregard for human life. Nice little anarchists, hope they have a nice little party, hope they rot in hell because of the grief they have caused people."
Police say they have arrested about 400 people in London so far and both civilians and officers have been injured.
Nine police forces from other parts of the country are providing support, as well as the City of London Police and British Transport Police.
Scotland Yard's acting police commissioner Tim Godwin says those responsible for the riots in London will be held accountable.
Unrest in other cities
In Birmingham, Britain's second city, police said they have arrested about 100 people after looters smashed shops and stole goods.
The disturbances spread from the centre to different parts of the city on Monday, the BBC reports. Shopkeepers in the Handsworth area made appeals to their communities to help protect their businesses.
A police station and several cars were set on fire. In one shopping centre, terrified workers were forced to lock themselves in for their own protection.
In Manchester, there were reports of cars being damaged and of up to 200 youths with masks roaming through Toxteth in Liverpool setting cars alight.
Police in Bristol said they were dealing with outbreaks of disorder involving about 150 people.
