Three were taken to hospital for treatment and were later discharged.
Bottles and other missiles were thrown at police during the disturbances, while a number of cars were set alight.
Two men aged 18 and 19 were due to appear at Belfast Magistrates' Court in relation with the disorder.
"Police can now confirm loyalist paramilitaries are orchestrating some of the violence we have seen in the past 24 hours," Assistant Chief Constable Will Kerr said.
"Violence has serious and unwanted consequences for us all and we will robustly investigate all incidents."
ACC Kerr previously described the disorder as "mob violence" which he said was "unacceptable".
We are warning anyone who does engage in criminal activity that they will face the full rigours of the law.
Assistant Chief Constable Will Kerr
But former UDA leader Jackie McDonald denied paramilitaries were behind disorder at Belfast's Sandy Row.
"There's absolutely no paramilitary involvement in the violence here last night," he told UTV.
"There were people from the Woodstock Road, Donegall Pass, the Village... Strangers are running about this place because of Facebook messages, and the people of Sandy Row are getting the blame.
"Obviously some of the young people in the area get involved in it but they were not behind it," he added.
Trouble also flared in the O'Neill Road area of Newtownabbey as a crowd of around 70 people blocked the road and attacked police with bricks and masonry on Friday night.
Two petrol bombs were thrown at police vehicles, which were damaged during the disturbances.
Eight men, who were arrested by police following the disorder in the area, have been charged with various public order offences.
Five men are due to appear at Belfast Magistrates' Court on Monday. A 16-year-old boy is due to appear at Belfast Youth Court on Monday and a 17-year-old teenager is expected to appear in January.
The latest trouble erupted in the wake of a Belfast City Council vote which restricted the flying of the Union Flag over City Hall to 17 days a year.
Nationalists wanted to remove the flag altogether but the Alliance Party, which holds the balance of power, put forward the motion which was passed.
A total of 28 police officers have been injured in loyalist rioting since Monday's vote, while a number of Alliance Party representatives and properties have been targeted.
Up to 2,000 people took part in a major loyalist flag protest in Belfast city centre on Saturday afternoon - which was expected to be the busiest shopping day of the year.
Assistant Chief Constable Will Kerr had appealed for protesters to stay away.
"Let people get on with every day business such as Christmas shopping," he said.
"Today I am urging everyone to be calm, take a step back and think about how this violence is affecting not just their own communities but the whole of Northern Ireland."