Several people were arrested following disturbances at Saturday's Apprentice Boys' parade in Derry.
Petrol bombs were thrown at the police who came under attack from nationalist and loyalist youths during four hours of sporadic violence.
The trouble started in the afternoon as the Apprentice Boys' annual Lundy's Day parade made its way around the Diamond area of the city centre. About 20 nationalist youths, some of them as young as 10 years of age, threw beer bottles injuring several of the 1,800 Apprentice Boys.
Police, some dressed in riot gear, forced the youths down Shipquay Street towards Guildhall Square where the crowd, which later increased to over 200, hijacked and set a delivery van on fire.
Two petrol bombs were thrown at police as they pushed the growing number of rioters across Guildhall Square into William Street. After the first parade ended, a large crowd of loyalists gathered in Bishop Street, about 300 yards from Guildhall Square.
Several bottles were thrown at police lines before the area was cordoned off with Land Rovers. There were further disruptions in Ferryquay Street when the Apprentice Boys were re-routed away from the Diamond by the police, acting on the instructions of the Parades Commission.
Mr Alistair Simpson, the Governor of the Apprentice Boys, protested to RUC Supt Peter Sheridan. "I want to protest against the futility of the Parades Commission's decision stopping us from going into the Diamond today," said Mr Simpson. As the marchers, who included the city's DUP mayor, Alderman Joseph Miller, turned away from the Diamond into Pump Street, the Castlederg Young Loyalists band tried to force its way into the banned area.
During scuffles, Supt Sheridan was struck with a traffic cone. "We had 40 marshals out there today," Mr Simpson said, "and I will have to hear from them first about what happened. We told the Parades Commission once you start re-routing, anything is liable to happen. I have to wait on all the reports from all the marshals. If the Parades Commission had let us go ahead through the Diamond, I would have said there would have been no trouble at all.