Shops and businesses in some areas are closing early in a bid to avoid the kind of violence and looting that spread through London on Monday.
PM David Cameron has pledged to restore order, recalling Parliament on Thursday in response to the "sickening scenes", which prompted unrest in other cities.
Among them were a graphic designer, college students, a youth worker, a university graduate and a man signed up to join the army. Some gave non-London addresses. Eighteen were remanded in custody.
So far 563 people have been arrested and 105 charged in connection with violence in the capital.
Deputy Assistant Commissioner Stephen Kavanagh said the use of plastic bullets - never before fired to deal with riots in England - would be "considered carefully" in the event of further disorder.
But he added: "That does not mean we are scared of using any tactic."
Acting Commissioner Tim Godwin had earlier ruled out calling in the Army.
AnalysisHighbury Corner Magistrates Court has dealt with a large number of cases arising from the riots in north London.
Those who appeared this afternoon were all male and generally in their 20s, although there were some youths.
Charges were most commonly burglary and criminal damage. There were a large number of guilty pleas entered.
The magistrates said that their powers of punishment were insufficient in the light of the fact that the offences were committed during a riot, which amounted to a "substantial aggravating feature".
A significant number of those charged were said in court to be of previously good character and had simply been drawn in to the offending.
In one defendant's case, a lawyer described his client as offending in "a moment of madness".
Mr Cameron met officers in the Met Police's Gold command in Lambeth on Tuesday afternoon, before speaking to emergency service personnel in Croydon.
He condemned the "sickening scenes of people looting, vandalising, thieving, robbing".
He told rioters: "You will feel the full force of the law. And if you are old enough to commit these crimes, you are old enough to face the punishment."
The recall of Parliament will allow MPs to "stand together in condemnation of these crimes and to stand together in determination to rebuild these communities", he said.
The prime minister returned early from his holiday in Tuscany to discuss the unrest, which first flared on Saturday after a peaceful protest in Tottenham over the fatal shooting of a man by police.
London has seen a wave of "copycat criminal activity" over the past three days, the Met Police said.
Officers believe some rioters have used BlackBerry Messenger - a service allowing users to send free real-time messages - to organise violence.
Meanwhile, two 18-year-olds were arrested in Folkestone, Kent, and a 16-year-old was being questioned in Glasgow on suspicion of inciting violence through internet social networking sites.
Tuesday evening has brought reports of a disturbance in Salford, Greater Manchester, where 70 to 80 young people are in a standoff with police, and West Bromwich where youths have smashed shop windows.
Developments related to Monday's disturbances included:
- Three people being questioned on suspicion of attempted murder after a police officer was injured by a car in Wembley, north-west London, while trying to stop suspected looters
- Part of London's Tramlink suspended as a result of a fire
- In Birmingham, 138 people were arrested after scores of youths smashed windows and looted shops in the shopping area
- West Midlands Police said a police station in Holyhead Road in Handsworth, Birmingham, was set alight
- Up to 200 youths with masks roamed through Toxteth in Liverpool, while Bristol police said they dealt with outbreaks of disorder involving about 150 people
- A Nottinghamshire police station was attacked in the St Ann's area and 200 tyres were set alight in the street
- Police dealt with "small pockets of disorder" in the Chapeltown area of Leeds
Mayor of London Boris Johnson, who also cut short a holiday to return, was heckled by the members of the public while viewing damage in Clapham Junction on Tuesday.
Some people have complained there have been too few police to deal with the violence.
Mr Johnson told those gathered that those responsible for the violence "face punishment they will bitterly, bitterly regret".
However, when challenged to do more for communities, Mr Johnson rejected "economic or social justifications" for the violence.
The Met said Monday's was "the worst" disorder in "current memory" after incidents across the capital.
It has led to sporting disruption, with Tuesday's Carling Cup matches at Charlton, West Ham, Crystal Palace and Bristol City postponed at the police's request.
England and Holland's friendly at Wembley on Wednesday has also been called off.
The trouble follows two nights of violence over the weekend which started after police shot a man dead in Tottenham.
A peaceful protest in Tottenham on Saturday over the death of Mark Duggan, 29, was followed by violence which spread into this week.