Three 13-year-old boys were among several youths charged for taking part in loyalist riots in Belfast.
The teens were arrested during disturbances on Friday and Saturday against new restrictions on flying the Union flag.
The Police Service of Northern Ireland (PSNI) said that while a protest at Belfast City Hall on Saturday passed off largely without incident, youths were involved in pockets of trouble on the Newtownards Road in east Belfast and in the O'Neill Road area of Newtownabbey.
Eight people were arrested and one police officer who was injured has been released from hospital.
Assistant Chief Constable Will Kerr said loyalist paramilitaries had been orchestrating some of the violence that has marred the city in recent days and appealed for calm.
"Police have gathered significant evidence as robust investigations continue," he warned.
Cross-party political figures also called for an end to riots and disturbances, which were in their sixth day.
More than a dozen men and juveniles were also detained on Friday night while eight officers were injured.
Several of the protesters - including a number of teens aged from 13 to 17 - have been charged with a range of public-order offences over trouble around the city.
The violence, which has left 28 police officers with injuries, overshadowed a visit to Northern Ireland by US Secretary of State Hillary Clinton.
Much of the anger has been directed towards the non-sectarian Alliance Party, whose councillors in Belfast voted to limit the number of days the Union flag could be flown over the city hall from 365 to 17.
A death threat was made against the party's only MP, Naomi Long, while a constituency office in Carrickfergus, Co Antrim, was destroyed in an arson attack and three councillors had their homes vandalised.
Belfast city councillor Laura McNamee was also advised to leave her home.
Separately, detectives in north Belfast are investigating a car hijacking in the Brown Square area on Saturday evening.
A driver was pulled out of his blue Nissan Primera car at the junction of Gardiner Street and Peter's Hill by two men, one with a knife. The car was later found on fire on the Shore Road in Newtownabbey.
Detectives probing the attack on the Alliance Party offices in Carrickfergus have arrested a 33-year-old man. He is being questioned on suspicion of arson with intent to endanger life and burglary last Wednesday.
Elsewhere, the PSNI confirmed it is investigating criminal damage at the home of Democratic Unionist Party (DUP) councillor Sammy Brush's house in Ballygawley.
A pane of double-glazed glass in the front door of the property was smashed in the early hours of the morning as someone had tried to kick down the door.
Party chairman and local MLA, Lord Maurice Morrow, maintained the incident was motivated solely by religious hatred and intolerance. "These attacks must stop," he said.
The Alliance Party also condemned the attack and urged anyone with information to contact police.
The PSNI later said a number of protests on Sunday over the flag controversy passed without incident.
More than 20 demonstrated at the bottom of the Shankill Road in Belfast while up to 300 people gathered on the Peace Bridge in Londonderry.
It is understood more than a dozen of these also walked through Derry city carrying the union flag.
"Police have carried out evidence gathering in relation to the actions of some of these protesters and a file will be prepared for the Public Prosecutions Service," a spokeswoman added.
Video: Protesters battle police in Shaftsbury Square on Friday