Dissident republicans were behind the violence that broke out in the Ardoyne area of north Belfast, Sinn Fein have claimed.
Ugly scenes erupted ahead of the Orange parade at the flashpoint outside the Ardoyne shops yesterday.
Riot police were targeted with a barrage of petrol bombs and missiles as Orangemen attempted to complete the final leg of their annual march.
At least nine officers were injured during the violence which saw petrol bombs, bricks, and at least one shot being fired by republicans.
In a bid to maintain order police fired 18 baton rounds and deployed a water cannon against rioters.
Serious disorder continued throughout the night with vehicles being hijacked and set alight in the street.
The violence received widespread condemnation from politicians, senior police officers and agencies.
Assistant Chief Constable Alistair Finlay described the rioting as “a face of bigotry, sectarianism and intolerance”.
Police also confirmed that earlier in the day a firearm was handed in to police after a group of children were found playing with it.
The police condemned those responsible for leaving the item as having “a total disregard” for the local community and putting local children at risk.
Speaking from the scene DUP Culture Minister Nelson McCausland said those behind the attacks wanted to drag Northern Ireland “back into the past”.
“I think we saw tonight the ugly face of dissident republicanism,” he said.
“This afternoon and this evening we saw the violence the sectarianism and intolerance of dissident republicans who are intent only in dragging Northern Ireland back to the past.”
ACC Finlay said it was “disappointing” that isolated outbreaks of violence had marred the day for all communities.
“Right across Northern Ireland there were hundreds of parades that passed off peacefully.” He condemned the minority of people behind the violence.
“They displayed the worst possible face of Northern Ireland — a face of bigotry, sectarianism and intolerance that is not representative of the vast majority of people who have embraced a peaceful future,” he said.
“It is communities who pay the price. It is their lives that are disrupted and it is their houses, businesses and local amenities that are damaged.”
He said police will carry out a “rigorous investigation”.
Sinn Féin Assembly member for the area Gerry Kelly said “a small number” of dissident republicans from outside Ardoyne were behind the ugly scenes.
“They orchestrated the trouble this evening,” he said. “These people want to see sectarian violence on the streets of Ardoyne and North Belfast.
“It was fairly obvious that these individuals are quite happy to try and orchestrate violence, whip up sectarian tensions and simply drive back to the areas they come from, leaving this community to pick up the pieces.”
Meanwhile, Twelfth of July celebrations in Londonderry were hailed as a great success, despite a handful of minor incidents which occurred in the city on the return march.
Orangemen were spat on by some members of the public as they passed by the Richmond Centre, and had several beer cans and bottles hurled in their direction.
Duncan Morrow, chief executive of the Community Relations Council, condemned the violence.
“Today’s disturbances suggest that it is time to find lasting solutions to these disputes along with all the other outstanding disagreements around culture, rights and law and order which threaten our peace,” he said.