Birmingham EDL protest: Crimewatch appeal to be broadcast
An appeal to trace more than 50 people who took part in an English Defence League (EDL) protest in Birmingham will be made later on BBC One's Crimewatch.
About 2,000 EDL supporters massed in Centenary Square on 20 July, where missiles and bottles were thrown at police. One officer was injured.
Members of Unite Against Fascism held a counter-protest in Chamberlain Square.
Police said 40 people had so far been arrested on suspicion of violent disorder at the demonstrations.
More than 1,000 extra police officers from forces around England were brought in to help West Midlands Police on that day.
The force said in one incident £150,000 of damage was caused to an office block in the city centre.
'Names to faces'
Violent protesters also used items from the nearby building site of the new Birmingham Library as missiles or weapons to cause damage, police said.
Det Ch Insp Simon Wallis said: "Regardless of motivation or cause, violence and criminal damage is unacceptable − particularly in a busy city centre when residents, including families with children, are innocently passing by.
"Our understanding is that people travelled from across the UK to attend the protest and so many of those who committed crime in Birmingham are unlikely to be from the local area.
"We are working with colleagues from partner forces up and down the country but, equally, we ask for the public to help us put names to those faces we are yet to identify."
West Midlands Police said images and video footage were being posted on the force website to try to identify people they wanted to speak to.