Police investigating people involved in unrest in central London on 26 March have released images of 18 suspects.
A group attacked police, broke windows and daubed banks and shops with paint in violence during and after a peaceful anti-spending cuts protest organised by the TUC.
Detective Chief Superintendent Matthew Horne said: "We are working tirelessly to identify those responsible for the appalling acts of criminal behaviour."
A total of 201 arrests were made.
Police have already charged 149 people, most of them for aggravated trespass, after a campaign group staged a sit-in at a luxury store on Piccadilly.
Scotland Yard has launched an investigation, Operation Brontide, and has now begun releasing images from various sources, including CCTV cameras.
The police said the violence "could not have been more markedly different" from the TUC event, in which between 250,000 and 500,000 people took part.
Det Ch Supt Horne, who is leading the investigation, said: "The vast majority of people, who came to London that day, did so peacefully, but a significant minority didn't - they came to cause violence and damage. There is an extensive operation to identify these people.
"With the help of the public they will be called to account for their actions on that day. I would urge anyone who recognises these individuals to contact my team."
He urged anyone with information to contact the Operation Brontide team on 020 8246 9386 or Crimestoppers, anonymously, on 0800 555 111.