The British government was holding crisis meetings Tuesday following a third night of serious rioting and looting in which cars and buildings were set ablaze in London and other cities, DPA reported.
Police said 334 people had been arrested and 69 charged in the capital. In the early hours of Tuesday, the rioting spread to other cities, including Birmingham, Bristol and Liverpool.
In view of the escalating crisis, Prime Minister David Cameron cut short his summer holiday in Italy to return to London late Monday where he will chair a meeting of the government's security emergency committee.
Ministers are expected to discuss reinforcing the police who have been struggling to contain the widespread sporadic outbreaks of trouble across London, as rioters use social network technology reach their targets before the police.
There was rioting and looting across London on Monday including in Clapham Junction, Newham, Lewisham, Bethnal Green, Peckham, East Dulwich, Clapham and Ealing.
Police said cars and buildings were set alight, shops were looted and, in Ealing, frightened restaurant-goers barricaded themselves in as hundreds of hooded youths roamed the streets outside.
One report said there had been a "massive increase" in burglaries in Clapham, an affluent neighbourhood in south London, during the night.
In Croydon, in south London, a huge furniture store was set alight.
Around 1,700 extra officers were deployed around the capital, as reinforcements from outside London were drawn in.
Scotland Yard Commander Christine Jones said the events were "simply inexcusable."
"Ordinary people have had their lives turned upside down by this mindless thuggery," she said. "The Met [Metropolitan Police] will ensure that those responsible will face the consequences of their actions and be arrested."
West Midlands police made around 100 arrests in Birmingham, in central England, in connection with looting and violence. There were disturbances in Bristol, in south-west England, and in Liverpool, in the north-west.
The violent demonstrations and looting started Saturday in Tottenham in north London following the death of criminal suspect Mark Duggan during a police sting operation.
The results of ballistic tests carried out after the shooting were expected Tuesday.
Doubts had reportedly arisen over the initial police claim that the alleged drug criminal died in a shootout.