Images have been released of people still wanted in connection with last summer's UK riots.
Around 40 suspects are wanted by five forces - Merseyside, Greater Manchester, Cleveland, Northumbria and Avon and Somerset.
Police said some of them are suspected of "significant" public order offences, including throwing bricks and serious assaults.
Last summer's unrest spread after false claims that the person who killed three girls in Southport was a recent asylum seeker.
Assistant Chief Constable Ian Drummond-Smith said: "One year on, we've still got some people who we have got good images of and we haven't yet identified.
"I think the key thing is having a good image of someone is one thing, knowing who they are is another.
"We're asking the public to have a look, and if they recognise anyone in those images, to let us know who they are and bring them to justice."
Nearly 1,900 people were arrested in connection with the violence and 1,110 have been charged so far, said the National Police Chiefs' Council.
The Crown Prosecution Service said 821 had been convicted by the end of March.
In the last few weeks, there have also been protests outside a hotel housing asylum seekers in Epping after one was charged with allegedly trying to kiss a 14-year-old girl.
Similar protests have happened in Norfolk and London.
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Mr Drummond-Smith warned "justice will be swift" for anyone considering similar behaviour and that officers were working hard to contain "small pockets" of disorder this summer.
"I think they've been isolated because of a swift police response to them, and I think that's the key thing," said the chief constable.
"If we can respond to serious disorder swiftly, I think we can contain that and prevent it from spreading across the country, so that's what we're working very hard on."
To view images of the suspects, go to police.uk/disorder-appeal
(c) Sky News 2025: Still wanted: UK riots suspects pictured in new police appeal