During the worst of the violence in Ardoyne police had to deploy water canon to disperse several hundred youths throwing missiles at them.
Police forced a number of the youths the youths back into the estates behind the interface. A hi-jacked van and car were set alight at both entrances to the area.
A PSNI spokesperson confirmed that at least 10 police officers had been injured in the violence.
PSNI spokesperson stated 'While up to a thousand local residents have gathered in the area, a core group of males, some aged as young as ten, are involved in the attacks on police.'
There was also trouble in Armagh, where missiles including petrol bombs were thrown at police.
The incident happened in the Friary Road area of the city following a security alert in which there was a small explosion. At least two cars were stolen and set alight.
An Orange Order spokesman said the parade in the area was not affected but buses returning home from the demonstration were diverted.
There was also violence in Rasharkin, and in the Diamond area of Derry.
There were four arrests.
Effort to market 'Orangefest'
12 July parades were held at 18 venues across Northern Ireland - with marches taking place this year on the 13th because the 12th was a Sunday.
Belfast was the key event but three flagship parades in Bangor and Banbridge, Co Down, and Larne, Co Antrim, also attracted tens of thousands of spectators.
Hundreds of bands and members of hundreds of orange lodges took part.
Public money has been provided to help sell 'Orangefest' to an international audience and the growing number of tourists visiting Northern Ireland.
