BELFAST, Northern Ireland — Belfast's worst riots in three years may have been encouraged by Catholic and Protestant paramilitary groups, police said Thursday.
Thirty-nine officers were injured, and five were treated at hospitals, police said.
Police in helmets and shields moved into the Ardoyne district, a Catholic enclave surrounded by similarly hard-line Protestant neighborhoods, Wednesday night to separate several hundred young men and teenagers from both sides of the divide.
The crowds threw stones and bottles — at each other as well as at police. Police returned fire with plastic bullets.
Police said the disturbances appeared to involve an element of organization on both sides.
"Last night we had six shots fired at us from the loyalist (Protestant) side, we had three shots fired at us from the nationalist (Catholic) side, we had over 100 petrol bombs thrown, acid bombs. Clearly this was, to some degree at least, organized rioting," assistant chief constable Alan McQuillan told British Broadcasting Corp. radio.
McQuillan said the rioting was the worst in the city since 1998.
Sectarian passions first flared in the area Tuesday when Protestant militants began throwing rocks and bottles at Catholic girls leaving their Ardoyne school, which lies on the far side of a high steel wall designed to keep the two communities apart.
Gerry Kelly, a senior member of the IRA-allied Sinn Fein party, accused loyalist paramilitaries of stirring up tension in advance of the summer marching season — which each year produces confrontations between Protestant fraternal groups and Catholic protesters determined to stop their marches through Catholic areas.
But Billy Hutchinson, a leader of the Progressive Unionist Party, which is associated with Protestant paramilitaries, linked the trouble to the IRA's refusal to disarm.
"Are they trying to create a situation where the IRA are made to hold on to their guns?" Hutchinson said.
John Reid, Britain's senior official in Northern Ireland, said the violence was "a reminder to all of us of what is at stake in this peace process."
That process, which produced a peace accord in 1998, is now grinding toward another crisis on the intractable issue of disarming the Irish Republican Army.
David Trimble, the Protestant leader of Northern Ireland's new regional government, says he will resign on July 1 if the IRA doesn't take concrete steps to dispose of its weapons. The IRA issued a statement Wednesday saying it would not meet the deadline.
The arms issue "will not be resolved by (Protestant) unionist ultimatums or on British terms," the outlawed group said in a statement to news media.
Reid spoke in London at a news conference with Richard Haass, the U.S. special envoy for Northern Ireland.
Haass said the United States supported the 1998 agreement, but said there was "no secret plan in Washington" to solve the remaining problems.
"I don't think that American mediation or something of that sort is called for," Haass said.