LONDON: Dozens of police were injured in Belfast on Friday evening in clashes with pro-British Protestants protesting against a parade by Catholic republicans.
Some 26 police officers were injured, five requiring hospital treatment, when they were attacked with bricks, bottles and other missiles by crowds in the city centre, police said.
Two members of the public were also hurt, while a number of parked cars were set on fire. Police used water cannon and fired baton rounds to try to disperse the rioters.
"Police have come under heavy and sustained attack by crowds intent on creating disorder," Assistant Chief Constable George Hamilton said.
He called on community leaders to work to reduce tensions.
Protestant loyalist protesters had tried to block part of the route of a planned republican parade marking the anniversary of the introduction by British authorities of internment without trial on August 9, 1971.
It was one of the most controversial policies of The Troubles, the three decades of civil unrest in Northern Ireland between pro-British Protestants and Catholic republicans favouring a united Ireland.
Nearly 2,000 people held without trial under the policy, the vast majority of them republicans.
Internment lasted until 1975. It was intended to restore order in the British province, but the deeply unpopular policy ultimately boosted recruitment to the paramilitary Irish Republican Army.
There were also clashes on Thursday night at an anti-internment bonfire near Belfast city centre, when eight police officers were injured and eight people were arrested.
Last month the city was hit by several nights of rioting, mainly by loyalist groups.
More than 3,500 people died during Northern Ireland's three decades of sectarian strife.
The 1998 Good Friday agreement, which set up a power-sharing government between republicans and loyalists, largely ended the violence, although sporadic attacks and bomb threats continue.