Theresa May says most rioters were not in gangs
The "majority of people" involved in the riots appear not to have been in gangs, the home secretary has said.
Theresa May told MPs it appeared the role of gangs was "not as high as people first thought". In London 19% of those arrested were gang members.
But there was "some evidence" gangs were involved in inciting rioting on social media, she said.
More than 2,700 people were arrested after violence and looting spread from London to other English cities.
Gangs got much of the blame for the spread of disorder - Prime Minister David Cameron promised a "concerted, all out war on gangs and gang culture" and former police chief of Los Angeles and New York Bill Bratton is to advise the government on the issue.
Work and Pensions Secretary Iain Duncan Smith has warned Britain is in the "last chance saloon" and told the Spectator last month there was "pretty good evidence" gangs were at the centre of the riots.
Mrs May told the home affairs committee on Thursday that the Metropolitan Police and other forces were looking at the number of people arrested with known gang affiliations - the percentage of which had fallen over time, as total arrests had risen. About 25% of those arrested were juveniles, she said.
The committee has already heard evidence that about 19% of those arrested in London were gang members - down from almost a third of those initially arrested.
"On current evidence it would seem that the majority of people involved were not individuals who've been involved in gangs, although obviously a number of people involved were involved in gangs," Mrs May said.
"But there is some evidence that obviously there was some gang activity taking place in terms of encouraging people to take part in these events and as we saw, some of that encouragement was being propagated on social media."
Arrests were expected to continue for some time, she said and, as a result, the picture of who was involved would keep changing.
The home secretary is involved in a cross-departmental group looking into gang issues. She said she would be hosting an international conference in October, "looking at other countries that have gang problems" - such as the US - but also at examples of work in London and Strathclyde, seen as a success story in tackling gang culture.
Earlier this week Justice Secretary Ken Clarke said that there was a sense that a "hard core of rioters came from a feral underclass".
Asked what caused the riots, Mrs May said that was "very difficult to say" and that there appeared to be different causes in different areas.
"It's not helpful for politicians to suddenly speculate over what happened," she said.
"Wider issues" rather than just policing tactics had to be looked at, but only "on the basis of a proper analysis of who was involved". But she said while it was possible that the involvement of gangs was "not as high as people at first thought", that did not mean the government should not be looking at the issue.
She said she would be "very cautious" about suggesting a direct link between the riots and the shooting of Mark Duggan in north London by police - the first violence broke out in Tottenham after a demonstration about his death, as no-one could "actually wholeheartedly say we know" what caused people to take part in the riots.
Tottenham MP David Lammy told the committee that "a death of this kind, we know from experience of London, can trigger unrest" - and said Mr Duggan's family had been "left floundering" due to a lack of information.
But he said he had learned of attempts to orchestrate violence by text message before the demonstration about Mr Duggan's death. The message, sent to a 14-year-old boy, referred to starting disturbances in neighbouring districts and did not appear to be linked to Mr Duggan's death.
Shadow justice secretary Sadiq Khan criticised Mr Clarke earlier, saying: "Casting simplistic assertions about a 'feral underclass' as Ken Clarke has about those involved in the riots is lazy. This kind of language absolves people from responsibility for their actions, implying that somehow they had not self control or no choice."
He said government cuts were undermining efforts to deal with young criminals - as gang intervention projects were reducing their services or being closed down - which was in turn restricting sentencing options open to judges where community punishments might be more suitable.
In August Mrs May said that she had "ordered" that all police leave should be cancelled and "robust tactics" used by all forces - something that was disputed at the time by police.
She told the committee on Thursday it was the Metropolitan Police which had proposed putting greater numbers on the streets. Asked whether she had ordered leave to be cancelled, she told the committee that in a conference call on the Wednesday morning - after the Met had cancelled leave and boosted police on London's streets to 16,000 - she had "made it absolutely clear to chiefs up and down the country that I expected them to follow that example".