People looking to protect themselves have been told they can use "reasonable force", including weapons, to defend themselves and their property even if they are not attacked.
Members of communities affected by the violence, some armed with hockey sticks, swords and other weapons, took to the streets in Eltham, Hackney, Southall and Enfield in London, and in Birmingham. The vigilante groups were urged not to get involved in "hand-to-hand combat" with rioters.
The Mayor of London, Boris Johnson, applauded people wanting to protect homes and businesses – although he warned against vigilante groups being "hijacked by people with a political agenda" as reports surfaced of racial abuse and alleged far-right infiltration.
In Eltham, south-east London, one local promised: "The gangs are going to get a proper hiding." Peter Webster, 34, who runs a shoe shop, said: "You can't just run around ruining people's businesses and livelihoods. If the looters get a good kicking, then that's how it's got to be."
A 31-year-old Millwall supporter, who declined to be named, said: "Everyone will come out tonight. If people come around here smashing our shops up, then they'll get what they deserve. We're happy to get into it with them."
In the end, however, it was the groups who maintained they were out to protect Eltham which were moved on. Riot police moved in and, despite a brief hail of bottles thrown at them, quickly cleared the streets.
Speaking during a visit to Enfield to survey the damage caused by riots, Mr Johnson said: "People who have the interests of the community and who want to look after each other, of course I want them out on the streets."
Advice from the Met, published on its website, reminded anyone who came under attack that they "can use reasonable force to protect themselves or others", adding that they "are not expected to make fine judgements over the level of force you use in the heat of the moment. So long as you only do what you honestly and instinctively believe is necessary." But senior officers expressed concerns that the groups were getting out of control. Deputy Assistant Commissioner Stephen Kavanagh said: "I do not support vigilantism and we do not want to see more violence on our streets."
About 200 vigilantes went out in Enfield where one man claimed he was chased and racially abused as he tried to enter a pizza shop. Jason Jules said he was pursued by people who shouted "get the Blacks and Pakis". He added: "But no one was looting or rioting."
One 17-year-old, who was out in Enfield, said: "We are not racists, we are realists. We are willing to fight. This is England, our England. We don't want people coming here and fucking up our country. We will be out again tonight."
Hundreds of Sikhs turned out in defence of homes, temples and jewellery shops in Southall. Some were carrying swords – since 1951 Sikhs have had the legal right to wear kirpans, a type of ceremonial sword. An estimated 700 Sikhs responded to the call in Southall, with about 200 at the temple.
Himmat Singh, the Gurdwara's president, said the defenders had acted in a spirit of "peace and harmony" and that had looters threatened the temple, they would have been invited to "calm down". He said: "The people who are making trouble are also part of the community. We would have asked them to calm down and sit together in peace and harmony – we are looking to peace in all the world all the time."
In Gloucester, plans for a civilian defence force patrolling in rugby club shirts were shelved last night after police stepped up their presence.
"People think Gloucester is a quaint cathedral town," said Will Cook, the manager of a DVD and computer game shop who planned to join the defence force, "but there are parts of Gloucester as rough as anywhere in Birmingham or Manchester or Liverpool. This shit needs to be sorted out."
In his spare time Mr Cook is a professional wrestler, and weighs 16 stone.
Run on baseball bats
Fear of looters is thought to be behind soaring demand for baseball bats, a piece of sports equipment little employed on Britain's playing fields but with a fearsome reputation as a DIY weapon.
Sales of one brand of baseball bat rose by 5,149 per cent in just 24 hours this week and others were not far behind on Amazon, where they accounted for seven of the top 10 most popular sports items.
A police-style baton enjoyed a similar increase in popularity, rising more than 5,500 places in the sales lists. The telescopic baton was described by the manufacturer as being useful for "effective self-defence with extra reach".
