Petrol bombs, stones and bottles have been thrown at police after they prevented an anti-internment parade from entering Belfast city centre.
The march was stopped by police at Oldpark Road in the north of the city after it breached a determination by a parades ruling body over its timing.
Organisers had asked supporters to leave peacefully when the parade ended.
But police were forced to deploy water cannon about an hour later when a crowd threw missiles at them.
Petrol bombs were thrown during trouble in the area where police stopped the parade
The march was organised by the Anti-Internment League to mark the introduction of detention without trial during the height of the Troubles.
The Parades Commission ruled the republican parade was to have passed Millfield junction by 13:30 BST, but it breached the ruling and did not start until about 14:00.
The march was stopped by police, who said their intention in blocking the parade was to "uphold the Parades Commission's determination".
During a short rally at the police line, a speaker told participants the parade had ended and asked those taking part to leave peacefully.
A short rally was held by parade participants at the police line along the Oldpark Road
But a crowd remained in the area and later threw petrol bombs and other missiles at police officers.
Deputy First Minister Martin McGuinness tweeted that those who organised the "so-called anti-nternment demonstration" bore "full responsibility" for the violence.
The Anti-Internment League said "all march participants behaved peacefully and with dignity" when the parade reached the police cordon, before taking "the responsible decision" to leave the area.
But the DUP MLA William Humphrey accused the organisers of making a "deliberate decision" to breach the timing condition imposed on the march.
"The organisers of this parade of shame have succeeded only in increasing inter-community tensions, causing huge expense for a massive policing operation and disrupting our city centre trade," the North Belfast MLA said.
Earlier, police made a direct appeal to the event's organisers to discuss the planned route and its timing with them.
They said they had made attempts to talk to the group but had not been successful.
Some roads in the city centre were closed from an earlier point in the day, including North Street, Royal Avenue and High Street.
Police had earlier gathered in Belfast city centre ahead of the republican anti-internment parade
Translink said there was disruption to some of its city centre routes, but that they have since resumed normal services.
In previous years, the parade has proceeded through the city.
At the same event two years ago, 56 officers were injured when loyalist protesters attacked the police.
The OldPark, Westland Rd, Antrim Rd has always been historically a hot spot.
I would for a change like to see photos of my x brothers doing a Fucking amazing Job.
Take care all PSNI brothers tonight.
Rick