Cameron said he would not rule out calling in army support -- an unprecedented event in UK -- if there were more disturbances like earlier this week.
He also said the government would also assume powers to intercept messages through social media such as Blackberry Messenger, Facebook and Twitter during times of crisis so that such messages are disrupted.
"It is the government's responsibility to make sure that every future contingency is looked at, including whether there are tasks that the army could undertake to free up police for the frontline," Cameron said in the course of his detailed statement in the rare recall of Parliament to consider the law and order situation in Britain.
Admitting that he had contemplated deploying the army as the riot situation deteriorated in the last few days, the Prime Minister said the law and order had spun out of control.
Masked youths looted shops, torched buildings and cars and attacked police, slurring Britain''s image with less than a year left for London to host 2012 Olympics.
BBC said Cameron told MPs that the police had got their riot tactics wrong, triggering a row between police chiefs and the government.
The Prime Minister said police chiefs had been "frank" with him about what went wrong on Sunday and Monday nights in London and elsewhere.
"There were simply far too few police deployed on to our streets and the tactics they were using weren't working," he said.
"Initially, the police treated the situation too much as a public order issue - rather than essentially one of crime." Sir Hugh Orde, head of the Association of Chief Police Officers, said it was police, not MPs, who had restored order.
Acting Met Police Commissioner Tim Godwin said that "if police officers had the benefit of hindsight as foresight we would obviously do things slightly differently", adding: "We always learn from what occurs." Asserting that the fightback had begun, BBC quoted Cameron as saying that the authorities would hunt down killers, looters and rioters.
He also pledged action against street gangs, saying there were evidence that they had coordinated attacks on police and looting.
"Combating them would be a national priority," Cameron declared as he said the government had given police powers to demand people remove face coverings after many looters were found by CCTV cameras to be masked during ransacking of shops and stores.
He also said that his government was also looking at giving wider powers to police including reviving powers to impose curfew when necessary.