British police flooded the streets to ensure weekend drinking does not reignite the rioting that swept London and other cities this week, shocking Britons and sullying the country's image a year before it hosts the Olympics.

Steve Kavanagh, deputy assistant commissioner of the Metropolitan Police, said 16,000 officers, instead of the usual 2,500, would remain on duty in London in their biggest peacetime deployment -- a measure of the perceived public order challenge.

Other forces, including those in the cities of Nottingham, Birmingham and Liverpool, said they would maintain a high level of policing over the weekend, although they said they were not anticipating further trouble after a couple of nights of quiet.

Even in normal times, alcohol-fuelled street disorder is commonplace across urban Britain at weekends.

British Prime Minister David Cameron, describing the four nights of looting, arson and violence, in which five people were killed, as "criminality, pure and simple", called the initial police response inadequate.

His remarks drew a sharp response from the police service, which is facing deep cuts in numbers as part of a government austerity drive aimed at cutting public debt.

"The fact that politicians chose to come back is an irrelevance in terms of the tactics that were by then developing," said Hugh Orde, head of the Association of Chief Police Officers, referring to Cameron and other senior ministers who cut short their holidays after two days of mayhem at home.

Looking for help further afield, Cameron has offered William Bratton, credited with curbing street crime as police chief in New York, Los Angeles, and Boston, the position of a consultant, said a spokesman for the firm Bratton now works for.

Bratton told NBC on Friday: "This morning I had a conversation with Prime Minister Cameron in which he thanked me for my agreeing to work with the British government as they deal with the issues of gang crime, gang violence and gang intervention."

Cameron himself has not escaped criticism. According to a ComRes poll for The Independent newspaper, 54 percent of Britons say he failed to provide leadership early enough to control the riots, while an ICM survey for The Guardian showed that only 30 percent thought Cameron responded well to the riots and 44 percent thought the opposite.

More than 1,200 people were arrested during the unrest. One London looter, 24-year-old Natasha Reid, turned herself into police because she could not sleep for guilt after stealing a television, according to her defence lawyer.

In another case, Chelsea Ives, 18, one of thousands of people enrolled as "ambassadors" to help visitors to the 2012 Olympics, was identified by her mother who saw her on television after allegedly throwing bricks at a police car. Ives denied charges of burglary and violent disorder.

Courts have sat through the night to process those accused of crimes ranging from assault to stealing a bottle of water.

Offenders include a millionaire's daughter, a charity worker and a journalism student, though most are unemployed young men.

Some police forces have taken unusual steps to crack down on the protesters and deter future violence.

Greater Manchester Police launched a 'Shop A Looter' campaign using social media sites like Facebook and Twitter to encourage people to inform on those suspected of looting, and posted pictures on its website (here) of people convicted of offences.

Those pictures included a 46-year-old man sentenced to four months in prison for assaulting a police officer and a 28-year-old man sentenced to eight months for stealing clothes.

"The fightback has well and truly begun," Cameron told an emergency session of parliament on Thursday, outlining a range of measures aimed at preventing any repeat of England's worst riots in decades. Targeting street gangs became a top priority.

The trouble began in London after police shot dead a black man and refused to give his relatives information about the incident, but then degenerated into widespread looting and violence in many parts of the capital and other major cities.

In an echo of the event that sparked the unrest, the Independent Police Complaints Commission said on Friday it was investigating an incident in which a man arrested by police in London on Wednesday became seriously ill in police custody.

The man is in hospital, where he remains in a serious condition, the IPCC said, stressing it had met with members of the man's family to address questions they might have.

HARSH MEASURES

The Conservative Party, which irked traditional right-wing supporters by going into coalition with the left-leaning Liberal Democrats last year, is desperate to show it is tough on crime.

A Conservative minister said on Friday he was exploring whether he could make it easier to evict people from government housing for rioting.

"That may sound a little harsh, but I don't think this is a time to pussyfoot around," Eric Pickles, communities minister, said, adding that the measure would require legal changes.

"These people have done their best to make people frightened on the streets where they live. They've done their best to destroy neighbourhoods, and frankly I don't feel terribly sympathetic towards them."

The coalition is keen to regain the initiative after early criticism that it was slow to respond to the rioting which has overturned Britain's image abroad as a generally peaceable and orderly society.

A 68-year-old man who was attacked as he tried to put out a fire set by rioters in London on Monday night died of his injuries, officials said on Friday.

Three men were killed in Birmingham, central England, when a car drove into them as they tried to stop rioters, and a man died after being shot during riots in Croydon, south London.

The scale and ferocity of the rioting, not only in inner-city areas but also in some middle-class suburbs, has generated a law and order debate with starkly different views.

"There's got to be a curfew put in place. I would have put in as many police as possible straightaway -- they did that eventually. I probably would have used teargas myself," said Graham Sawyer, 46, a construction site project manager from Romford, east of London.

"I'm old enough to remember (former prime minister) Margaret Thatcher. She certainly wouldn't have let it happen. I think she would have possibly gone too far, but I think she would have stopped it straight away," he said.