Ten police officers were injured during a third night of rioting in Belfast and other parts of Northern Ireland.
New Barnsley police station was attacked
The trouble, which stemmed from the re-routing of a contentious Orange Order parade, began on Saturday.
Sixty-three people have been arrested following the rioting over the past three days.
Sixty people were arrested for public order offences and three in connection with serious terrorist offences. Police said that more arrests would be made.
On Monday, trouble flared in Belfast, Lisburn, Newtownards and Newtownabbey.
But the violence was not on the same scale as at the weekend, police said.
In north Belfast, arrests were made in the Cambrai Street/Boundary Way area and the army dealt with a pipe bomb.
Petrol bombs, fireworks and other missiles were also thrown and one police officer was knocked unconscious when he was hit with a brick.
In west Belfast, about 40 petrol bombs were thrown and New Barnsley police station came under attack.
Police moved water cannon on to the Shankill Road after being attacked by rioters throwing petrol bombs.
In east Belfast, paint and bottles were thrown at police and an attempt was made to hijack a bus. A car was hijacked in Ravenscroft Avenue.
Cars have been set on fire in north Belfast
In Lisburn, there were petrol bomb attacks and a woman was pulled from her car which was then set alight.
In Newtownabbey, Bangor, Newtownards and Millisle, there was sporadic violence. Cars were hijacked, buildings set alight and petrol bombs thrown.
One car was burned in the Ballykeel 1 estate in Ballymena. The police recovered ten crates of milk bottles and two drums of petrol. A firework was also thrown at the police.
Ten officers were injured in Monday's violence, a total of 50 officers were injured in the weekend riots.
As part of their ongoing investigations, police are considering breaches of the Parades Commission's ruling on Saturday's Whiterock parade.
Chris Kerr from the Fire and Rescue Service said that, as far as fire crews were concerned, tensions were "greatly reduced" on Monday night.
Police were unable to stop vehicles being burnt out
"We were assisted in many areas to deal with incidents where the public required our attention," he said.
"And, indeed, also to avoid potential conflict situations by avoiding attending cars on fire in the open where, clearly, our attendance was not required."
Northern Ireland Secretary Peter Hain is reviewing whether Ulster Volunteer Force or Ulster Defence Association members orchestrated the violence.
After examining the footage of weekend rioting, he said on Monday: "The evidence I have seen is absolutely clear-cut. If it wasn't clear-cut before, it's absolutely categorical now.
"As a result, I'm now going through, and indeed have been over the past week, a process in which I will be making an announcement in the next few days."
The US consul general Dean Pittman said he was "disheartened and saddened" by the violence of the past few days.
He was speaking during a visit to an integrated primary school in Londonderry.
He described the image sent out across the world at the weekend as "terrible". It was now important for leaders to come together and build for the future, he said.
Unionists said there had been a build-up of resentment within their community because of the government's handling of the peace process.
Trouble began in the city on Saturday after the Parades Commission refused to change their decision not to allow the Orange Order's Whiterock parade to pass through a nationalist section of Springfield Road.