Aug. 10, 2011  -- Top London officials have warned the city's citizens against administering vigilante justice in the midst of widespread riots after several groups organized to protect their property by any means necessary.

"We don't want to see vigilantism," London mayor Boris Johnson said today in a press conference, according to The Telegraph. "People defending their homes and shops must only use reasonable force."

Metropolitan Police Deputy Assistant Commissioner Stephen Kavanagh also urged restraint, saying "vigilantism" could lead to further violence, according to a report by the BBC.

READ: London Riots: 3 Dead as London Police Go on Offensive

Though the streets of London were quieter today due to a massive influx of police, the authorities' comments come just hours after reports emerged that three Pakistani men had been killed after being hit by a car while protecting a neighborhood in Birmingham, England.

"At some point, and in circumstances that as yet I can't fully explain, a vehicle has been driven into that group of males, which tragically has led to three of those men losing their lives," West Midlands Police Chief Constable Chris Sims said, according to the BBC.

Tariq Jahan, the father of one of the men, told the BBC his son and many others had come out of a nearby mosque to protect the area. One man has been arrested in connection with the deaths.

During the height of the violence Monday, video emerged of what appeared to be a Turkish group chasing rioters down the street and away from Turkish-owned shops in east London. A Bangladeshi group also reportedly gathered around their own shops to form a human barrier against rioters. Tuesday night, hundreds of Sikhs gathered outside a Sikh temple, some standing defiant with swords raised or their arms crossed over their chest.

Sikh Satjinder Singh told the BBC the group gathered because they had been tipped off looters may come to attack the neighborhood.

"The feeling was that [the police] were spread so thin that there needs to be a community presence," Singh said. "It is not vigilantism, but it is effectively just protection of property.

READ: London Riots: Who's in Charge Here?

The English Defence League, a right-wing anti-immigration group, wrote on its website that its supporters have "already taken to the streets to help defend their communities and prepare for the clean-up operations that must follow the last few days of rioting [and] looting."

"We are hoping to safeguard local businesses through a strong physical presence, and discourage trouble-makers from gathering in our town and city centres," the post says. "No one should need reminding that the EDL condemn [sic] the use of violence: we need to stand with our communities, not do them a disservice like the rioters and looters continue to do."

But according to a report by The Telegraph, one meeting of EDL supporters and citizens in Eltham in south-east London nearly turned violent when the group attacked a passing bus full of black youths, but was stopped by police.

Though Kavanagh said he had seen "some outstanding acts of courage... to stop people out there from breaking the law and persuading [rioters] to go home," he does not support vigilantism and believed such acts could draw valuable resources away from putting down the riots.

"What we don't need is for our resources to be diverted by groups of people, some of whom having been drinking," he said. "We do not want to see more violence on our streets."

READ: What Happened to Mark Duggan, The Man Who Sparked the London Riots?

Still, perhaps in a sign of the public uncertainty, sales of personal defense weapons including baseball bats -- in a country not known for playing baseball -- and nun chucks have skyrocketed on the British version of Amazon.com. Many customers are presumably still waiting for delivery as the riot continues.

ABC News' Miguel Marquez, Angus Hines and Josh Haskell contributed to this report.

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