Cameron addressing Parliament
British Prime Minister has said police had admitted to him that they got their riot tactics wrong, as he announced a raft of measures to help homeowners and businesses, reports the BBC.
The riots were "criminality pure and simple" however there were "far too few police" on the streets, he said, during an emergency recall of Parliament.
He announced a crackdown on facemasks and a review of curfews.
More than 1,300 arrests have been made since the unrest began on Saturday.
The prime minister earlier chaired a meeting of the government's emergency committee Cobra to discuss the violence with cabinet ministers.
Cameron told MPs that it had become clear that there had been problems in the initial police response to the disorder.
"There were simply far too few police were deployed on to our streets and the tactics they were using weren't working," he told MPs
"Police chiefs have been frank with me about why this happened.
"Initially the police treated the situation too much as a public order issue - rather than essentially one of crime.
"The truth is that the police have been facing a new and unique challenge with different people doing the same thing - basically looting - in different places all at the same time."
Meanwhile, Keith Vaz, chairman of the Commons Home Affairs Select Committee, has told the BBC its members have voted unanimously to hold an inquiry into the causes of the riots.
It will also look at the role of social networking, the police response and police resources.
Deputy Prime Minister Nick Clegg said the government's first obligation was to "show that we can keep our streets safe".
"It's a basic need that we've all got to know that our homes, our shops, our communities can be kept safe at times like this," Clegg told BBC Radio 4's Today programme.
"I think the immediate priority is to see through what the police have been doing successfully in the last few days, which is getting on top of the situation, making sure that the streets are safe again, getting people into court and getting them behind bars where appropriate."
He said longer-term debates were needed in the coming weeks and months but this would start in Parliament later.
On Wednesday, Cameron said the "fightback" was under way and said every action would be taken to restore order, with contingency plans for water cannon to be available at 24 hours' notice.
It is the second time in less than a month that MPs have been recalled for an emergency session - the first was for the phone-hacking scandal at the News of the World newspaper.
Courts sat through the night in London, Manchester and Solihull in the West Midlands to deal with people arrested during the four nights of disturbances, with those appearing in court mainly facing disorder and burglary charges.
Cameron said anyone convicted of violent disorder would be sent to prison.
But Met Deputy Assistant Commissioner, Stephen Kavanagh said some officers who had been on the streets had voiced disappointment at the sentences handed out so far.
Kavanagh added that there had since been "constructive conversations" between the home secretary, the Met commissioner and the courts.
"We're very keen to make sure that communities within our cities feel confident in the policing and that we can then get back to some sense of normality," he told BBC News.
London Mayor, Boris Johnson praised the police, and insisted the authorities were not "complacent" despite the violence subsiding.
"Nobody should be in any doubt that the problem is over or that we are remotely complacent about this," he told reporters after the Cobra meeting.