Police chiefs today pledged to make “significant” arrests after officers were attacked with petrol bombs in an outbreak of street violence in the flashpoint Ardoyne area of north Belfast.
As the Parades Commission defended the decisions to allow two rival loyalist and republican marches to take place just hours apart in the same area, Chief Constable Matt Baggott said many of those involved in the disturbances will face the courts.
He said: "There was no excuse for the rioting or the violence, even though it was contained in a relatively small area of Northern Ireland."
Ten PSNI officers were injured. Dissident republicans, opposed to the Sinn Fein peace process strategy of Gerry Adams and Martin McGuinness were among the crowds attacking the police.
Four men were arrested, but video footage will be examined to identify others involved in the trouble.
It started after hundreds of anti-riot police moved in to keep the factions apart as Orangemen returned home to a neighbouring area following a big Orange Order demonstration in the city - one of several across Northern Ireland on Thursday marking the anniversary of the Battle of the Boyne.
Although it lasted for several hours, the violence at Ardoyne, a Protestant/Catholic flashpoint, was not on the same scale as in previous years. But officers were on the receiving end of some vicious attacks. Three blast bombs were thrown and up to 10 shots were fired by a gunman. Three cars were hijacked.
Assistant Chief Constable Will Kerr said: "It's three days of annual madness where everybody thinks the police are legitimate targets."
All sides, including the Northern Ireland First Minister Peter Robinson, hit out at the ruling by the Parades Commission to allow the two parades to take place within such a short period of time and in such a highly charged atmosphere.
But the chairman Peter Osborne insisted the decisions were right in the circumstances. And he challenged the politicians to take responsibility to adjudicate on contentious marches.
Mr Osborne said: "It is complete and utter nonsense to blame the Parades Commission for the violence last night. There has been violence in this location for many, many years now."
He added: "It is time for politicians to take ownership of contentious parades - that's the way forward."
The Commission chairman was backed by the Northern Ireland Secretary Owen Paterson.
He said: "The Parades Commission was lawfully constituted by Parliament in 1998 in order to take decisions over parades out of the hands of the police and politicians.
"Should local politicians agree to alternative arrangements, and take responsibility for parading as was envisaged in the 2010 Hillsborough Castle Agreement, the Government will support them.
"In the meantime we shall stand by the independent Parades Commission as the sole legal authority in Northern Ireland to make determinations on parading."