Police Clash With Catholics in N. Ireland : Europe: Ten civilians, 12 officers are hurt in fracas before march by Protestants. Incident is called threat to peace.

BELFAST, Northern Ireland —  Police clashed Saturday with Roman Catholics trying to block a Protestant march through their neighborhood, giving new urgency to efforts to bring peace to Northern Ireland.

Catholic politicians called the violence the worst since the Sept. 1, 1994, Irish Republican Army cease-fire and said it seriously threatened chances for peace.

Ten civilians and 12 police officers were injured in skirmishes that broke out after police tried to remove 200 Catholics who had blocked a bridge over the Lagan River. When protesters pelted them with bottles and stones, police fired rubber bullets, wounding one man in the face.

The fighting lasted about 20 minutes before police gained control and allowed a token column of about 30 Protestants to march down the Ormeau Road before taking buses to join thousands of their fellows in the province’s second city, Londonderry.

About 20,000 Protestants converged on Londonderry to parade through the now mainly Catholic town where so-called Apprentice Boys slammed shut the gates of the city against Catholic King James II three centuries ago.

Members of the 60% Protestant majority in Northern Ireland see the march as an expression of their birthright and desire to remain British. Catholics say it is a revival of sectarian hatred.

Police forcibly removed about 200 Catholic demonstrators from the ancient walls of Londonderry where they were trying to prevent Protestants from marching along a section that overlooks the predominantly Catholic Bogside area.

Shortly afterward, thousands of Protestants wearing bowler hats and gray suits as a sign of their Britishness began to march through the town to the beat of military-style pipe bands.

Fighting that exploded during a Londonderry march on Aug. 12, 1969, sparked rioting in Catholic areas all over the British-ruled province, beginning 25 years of sectarian “troubles.”

The fighting Saturday increased pressure on politicians to restart Northern Ireland’s stalled peace process.

As the first anniversary of an Irish Republican Army cease-fire approaches, parties remain deadlocked over Britain’s refusal to admit the IRA-allied Sinn Fein to all-party talks until the outlawed IRA surrenders its weapons.