"The fightback has well and truly begun," he said in a statement to an emergency session of parliament, telling rioters: "You will pay for what you have done."
Cameron is under pressure to soften austerity plans, toughen policing and do more for inner-city communities, even as economic malaise grips a nation whose social and perhaps racial tensions have exploded in four nights of bewildering mayhem.
The British leader said he would keep a higher police presence of 16,000 officers on London streets through the weekend and would consider calling in troops for secondary roles in future unrest to free up frontline police.
Among other measures, he said he would give police powers to demand the removal of face masks or other coverings if their wearers were suspected of crime, and pledged to crack down on criminal "street gangs" to "help mend our broken society".
He also promised compensation for people whose homes or businesses were damaged by rioters, even if they were uninsured.
Cameron had ordered a rare recall of parliament from its summer recess to debate the unrest which flared first in north London after police shot dead an Afro-Caribbean man.
Britain's finance minister, George Osborne, will also address parliament amid concern the rioting could damage confidence in the economy and in London, one of the world's biggest financial centres and venue for next year's Olympics.
With the public seething over the looting of anything from sweets to televisions, Cameron has dismissed the rioters as no more than opportunistic criminals and denied the unrest was linked to planned spending cuts, mostly not yet implemented.
But community leaders say inequality, cuts to public services and youth unemployment also fed into the violence in London, Birmingham, Manchester and other multi-ethnic cities.
"Blacks, Asians, whites, we all live in the same community. Why do we have to kill one another?" said Tariq Jahan, whose son was one of three Muslim men run over by a car and killed while apparently protecting property in Birmingham.
"Step forward if you want to lose your sons, otherwise calm down and go home, please," he said.
Many Britons are appalled at the scenes on their streets, from the televised mugging of an injured teenager to a photograph of a Polish woman leaping from a burning building.
Moral high ground
But occupying the moral high ground is tricky in a country where some lawmakers and senior policemen have succumbed to material greed with expenses and bribery scandals, expecting to get away with it and top bankers have taken jaw-dropping bonuses even as the taxpayer has had to bail out financial institutions.
As the clear-up proceeds, the Conservative-Liberal Democrat coalition government must find quick fixes to avoid further unrest while also addressing longer-term problems in what Cameron has called "broken Britain".
"There are pockets of our society that are not just broken but frankly sick," Cameron said on Wednesday. He had waited two days before returning from holiday to deal with the crisis.
So far Cameron has authorised police to use baton rounds and water cannon where necessary. One in three people want police to use live bullets on rioters, according to a YouGov opinion poll published in The Sun tabloid newspaper.
A surge in police numbers – and heavy rain in many places – helped calm streets on Wednesday night, but the previous episodes of often unchecked disorder have embarrassed the authorities and exhausted emergency services.
Businessmen and residents had come together to protect their areas. Police in some areas complained vigilantes were only complicating their task and asked people to stay at home.
Police have arrested more than 1,000 people across England, filling cells and forcing courts to work through the night to process hundreds of cases. Among those charged were a teaching assistant, a charity worker and an 11-year-old boy.
The local council in Lewisham, south London, sent out a text message to residents reading: "Do you know where your children are?" – although in some cases parents had joined the looting alongside their offspring.
The opposition Labour party, eager for the government to soften its approach to tackling a record budget deficit, said cuts to police budgets had contributed to the violence.
"The scale of government cuts is making it harder for the police to do their jobs and keep us safe," said Yvette Cooper, Labour's home affairs spokeswoman.
Long-term tensions between police and youth, a dearth of opportunities for children from disadvantaged areas and visible inequalities where the wealthy often live in elegant houses just yards away from run-down city estates have been highlighted.
But Cameron's view of the rioters as thrill-seeking thugs who are indicative of a breakdown in Britain's social fabric and morals has struck a chord with many people.
Tensions have grown in Britain for some time, with the economy struggling to clamber out of an 18-month recession, one in five young people out of work and high inflation squeezing incomes and hitting the poor hardest.
COMMENTS (5)
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ
BRITTANNIA rules the waves? the waves are ruling brittannia!
may be looted money of india getting to an end.
@ paras vik Now we understand unemployment and (bhook) is roots cause of all problems and thats why we have in indo pak all the things exist metrialistic world and civilized hahahahahahaha.
And we thought atleast the Britishers were civilized! :P