Petrol bombs and other missiles have been thrown at police during rioting in the Ardoyne area of north Belfast.
The police fired a number of plastic bullets and a photographer was hit.
The trouble broke out after police in riot gear took up position ahead of an Orange parade walking past the Ardoyne shops on Tuesday evening.
Police said a number of officers were injured. One received minor burns to his face when his head was engulfed in flames when hit by a petrol bomb.
Stones, bottles and fireworks were thrown at police. Water cannon was used to push back the crowd of about 200 people.
In 2010, there were several days of rioting after the parade was allowed to walk past the shops.
The Greater Ardoyne Residents Collective (GARC), which opposes the Orange parade passing through the nationalist Ardoyne, held a protest in response to the Parades Commission decision to allow the march to pass the shops.
On the Twelfth of July, the Protestant Orange Order takes part in demonstrations across Northern Ireland, commemorating Prince William of Orange's 1690 Battle of the Boyne victory over catholic King James II.
PSNI Assistant Chief Constable Alistair Finlay said the scale of the violence had been "intense".
"There were a lot of petrol bombs, masonry and missiles thrown at police," he said.
"It was a scale which we regrettably have seen before.
"You can see the level of threat my officers are under and the risk they take in securing the safety of others."
Sinn Fein MLA Gerry Kelly said a parade in the area would continue to be a problem.
"The difficulty was that there was an Orange parade," he said.
"People have made great efforts, but a parade coming through a catholic area is a problem.
"I would appeal to the Orange Order, especially in Belfast where there seems to be an attitude of no talking, they need to talk."
The DUP MP for North Belfast Nigel Dodds said people had to realise that the Crumlin Road was a "shared space and not just a nationalist road".
"The people engaged in the violence didn't even see the parade go past," he said.
"There was a peaceful protest against the parade and it dispersed.
"This violence was intended, created and brought into existence by a small group of militant extreme republicans who were determined to have it, come what may."
ACC Finlay said there had only been two or three arrests following the Ardoyne trouble, however the low number was due to the tactics police used to keep people safe and restore order.
He said CCTV footage would be watched closely to identify rioters.
There were also pockets of violence in Belfast and Londonderry.
In the Markets area of Belfast, a number of youths threw stones and missiles at police in Stewart Street and a car was set on fire.
Police arrested three juveniles and two men on suspicion of riotous behaviour.
In Derry, seven people, including a 14-year-old boy, were arrested for rioting. A crate of petrol bombs was also recovered in the Fahan Street area of the city.
In Armagh, there were reports of public disorder in the Friary Road and Killylea Road areas. And in Ballymena a car was burnt out in Dunclug.
On Monday night, 22 police officers were injured during serious rioting in several nationalist areas of west and north Belfast.