Politicians have condemned the trouble which erupted in Derry as the Olympic torch was carried through the city.
Scuffles broke out after dissident republican protesters blocked the torch's planned route near the Guildhall.
It was forced to go a different way in order to reach the Peace Bridge.
The police said they believed a number of dissident republicans were involved. One person was arrested.
It was the first time the relay route was disrupted since it arrived in the UK.
The dissidents were protesting against policing on day 17 of the relay.
Foyle MLA Mark H Durkan said those respsonsible yesterday, abused their right to peaceful protest....