Dozens have been injured in the second consecutive night of violence in Portadown, County Armagh.
Violence flared when Orangemen converged on the town yesterday evening after their annual marches to commemorate the Battle of the Boyne.
Protestant youths began throwing missiles at the police as they attempted to section off Catholic areas.
Disturbances are expected into the night with nationalist and loyalist rioters directing their anger against the security forces and each other.
Vehicles have been overturned and police have been attacked with darts, bottles and stones. Four were seriously injured including one who was dragged from his car and stabbed in the neck.
RUC officers responded with baton charges and about 150 plastic bullets. A total of 127 police and civilians have been injured over the two nights.
Yesterday evening there were skirmishes between Catholic and Protestant factions as they hurled petrol bombs over wasteland in anticipation of today’s parade.
The march in the Portadown area passed off peacefully this afternoon after the Orangemen accepted a compromise from the RUC late last night.
The authorities expected trouble after sealing off the Tunnel section of Obins Street yesterday. This is the traditional outward route of the Portadown parade to Drumcree church.
When the RUC allowed Orangemen down Obins Street last Sunday there were angry scenes between police, loyalist marchers and Catholic residents.
Today, hundreds of troops joined the 1,000-strong force of officers lining the re-routed parade.
It took the 400 Orangemen from eight lodges 25 minutes to walk down the mainly Catholic Garvaghy Road.
Courtesy BBC News
In context
The Orange Order was founded near Portadown in 1795 after a clash between Catholics and Protestants at the Battle of the Diamonds.
With about 75,000 members it remains the largest Protestant organisation in Northern Ireland.
Every 12 July it celebrates the victory of Protestant William of Orange over Catholic King James at the Battle of the Boyne in 1690.
Tensions were high in 1986 because loyalists claimed concessions were being made to Catholics through the 1985 Anglo-Irish Agreement.
In 1997 an independent Parades Commission was established.
The Garvaghy Road continues to be a source of unrest and Orangemen have not been allowed to march down there since 1997.
