Violence flared for a second night in a row on Tuesday near a Catholic enclave in east Belfast, in what might be the worst violence in a decade in Northern Ireland, BBC News reported.
Two people were shot and homes were attacked with gasoline bombs in the sectarian violence that first erupted on Monday night, according to the Associated Press.
About 700 people were on the street throwing fireworks, gasoline bombs and other missiles, the police said, adding that there were reports that two men had sustained burn injuries.
Roads were closed and the police were trying to restore order. British broadcasters showed video in which hooded and masked men were throwing stones and missiles at each other, with many attacking police vans.
Chief Superintendent Alan McCrum said the trouble was "orchestrated" by the loyalist paramilitary group, the Ulster Volunteer Force, or UVF, BBC News said.
The clashes began on Monday night following a UVF raid on the Short Strand, a small Catholic and republican enclave on the edge of predominantly Protestant and pro-British east Belfast, the Belfast Telegraph said.
Catholic leaders said the violence was unprovoked, but Protestant leaders said the Protestant rioters appeared to be retaliating for smaller attacks by Short Strand youths on Protestant homes, the Associated Press said.
The area affected by the rioting is one of more than 30 parts of Belfast where barricades were erected to separate Irish Catholic and British Protestant populations. The barricades, known as "peace lines," have grown in number and size, even after the success of the 1998 peace accord in Northern Ireland.
As the riots erupted in the divided Catholic and Protestant area, many are asking why the UVF, a pro-British paramilitary organization, has refused to go away despite having supposedly destroyed its weapons and disarmed completely in 2009, the Christian Science Monitor reported.
According to the Christian Science Monitor:
In a sign of the progress in combating sectarian divides, politicians from across the political spectrum have condemned the attacks, saying paramilitaries have no role in today's Northern Ireland.
The Police Service of Northern Ireland appealed to "anyone with any influence" work with them to stop future outbreaks of sectarian violence. Still, questions are being raised about the possible power struggles in the group that could disrupt the peace in the broader community.