More than 40 people have been arrested after rioting saw police attacked, buildings looted and vehicles set alight in Tottenham, north London.
Twenty-six officers and three others were hurt in the violence which erupted after a protest over the fatal shooting by police of Mark Duggan on Thursday.
Residents surveyed the damage after homes were looted and shops burnt down.
The Metropolitan Police warned over "ill-informed speculation" on social networking sites of further problems.
All injured officers have now left hospital, the force said.
The people arrested remain in custody for offences including violent disorder, burglary and theft.
Meanwhile, the family of Mr Duggan said they were "not condoning" the violence that erupted.
"Please don't make this about my brother's life, he was a good man," his brother Shaun Hall said.
BBC crime reporter Ben Ando said there were rumours in the community that a teenage girl who was part of the peaceful protest had been in a kind of confrontation with police.
He said: "That appears to be the flashpoint. That was the moment at around about just after eight o'clock when it seemed that elements in the crowd decided to pick on two police cars. They were then set on fire."
The Independent Police Complaints Commission is investigating Thursday's shooting.
A police officer was also shot in the incident, which happened in what was called a "pre-planned" event, under Operation Trident, which investigates gun crime in the African and Caribbean communities.
Police had stopped a minicab which Mr Duggan had been travelling in.
Met Commander Adrian Hanstock warned people not to believe rumours.
He said: "Throughout the day we have been monitoring social networking sites and I'd like to say right from the outset, we're conscious of some really ill-informed speculation on those sites relating to potential further problems."
On Saturday night, shops and homes were raided and cash machines ripped out in Tottenham. There were also thefts from shops in nearby Wood Green.
London Fire Brigade said it had attended 49 fires in the area.
Some smoking buildings were still being dampened on Sunday, while residents surveyed the damage from behind a police cordon.
During the riot, which erupted at about 20:20 BST, people threw petrol bombs, reducing many buildings and vehicles to charred wrecks.
A double-decker bus, two police cars and a carpet shop were among the vehicles and buildings destroyed.
Crowds of looters smashed shop windows in a retail park near Tottenham Hale tube station.
The front window of Currys electrical store was smashed and the door of Argos was shattered after looters raided the stock room.
Every handset was stolen from a mobile phone store.
- Home Secretary Theresa May condemned the violence saying: "Such disregard for public safety and property will not be tolerated and the Metropolitan Police have my full support in restoring order."
- Labour MP for the area David Lammy said the community which "was already hurting has had its heart ripped out". He added: "This is an attack on Tottenham, on people, shopkeepers, women, children, now standing homeless."
- A Downing Street spokesman called the rioting "utterly unacceptable".
- London's deputy mayor Kit Malthouse said: "It's absolutely outrageous to see it on the streets of London. We'll do as much as we can to ensure there's no recurrence tonight."
- An 18-year-old man, who did not want to give his name, said: "Police know what they should have done, they should have come to speak to the community themselves. They don't care."
- The Reverend Nims Obunge, Pastor at the Freedom's Ark Church, in Tottenham, said: "It is right that this community should have questions they have answered. Until those questions are answered I don't think we can effectively rebuild the community."
Teenagers and adults were said to have turned up in cars to Tottenham's retail park and filled their boots with stolen items, unimpeded by police.
Others arrived on foot and piled shopping trolleys high with looted electronic goods, a local woman, who did not want to be named, said.
Another local resident told the BBC that looting had continued beyond daybreak on Sunday.
Meanwhile, shops including Vision Express, the Body Shop and Boots, in nearby Wood Green's High Street were also raided. Two cars there were also burnt out.
The BBC's Andy Moore said that since riots in 1985, relations between the local community and police had been generally good, but last week's shooting of Mr Duggan raised tensions.
A friend of Mr Duggan, who gave her name as Niki, 53, said those who had joined Saturday's protest, which began with a march from Broadwater Farm area, wanted "justice for the family".