Protestants will share power with the Catholics of Sinn Fein "over our dead bodies," Ian Paisley thundered Wednesday as tens of thousands of Protestant marchers celebrated the most divisive day on Northern Ireland's calendar.

Police and politicians reported little violence and lower-than-usual tensions as Protestants from the uncompromising Orange Order brotherhood mounted more than 600 parades for "the Twelfth." Almost all shops, pubs and restaurants closed for the official holiday, which commemorates the July 12, 1690, victory of a Protestant king, William of Orange, over his dethroned Catholic rival, James II.

Catholics generally despise the marches, particularly the Orangemen's so-called "kick the pope" bands of fife and drum. Sinn Fein, the Irish Republican Army-linked party, since 1995 has mobilized Catholics to block passing parades, a tactic that has helped inspire widespread violence in years past.

But on Wednesday, senior Sinn Fein leaders were active on the ground at several likely flashppoints, telling Catholics to stay off the streets and not throw objects. In some places, IRA veterans kept Catholic crowds in line.

CountryWatch: Ireland

The most dangerous confrontation zone, when a few hundred Orangemen passed an IRA power base called Ardoyne, brought rival mobs onto the streets, separated by heavy police lines.

As the parade passed to the cadence of a lone drummer, Catholics shouted insults and threw a few firecrackers and paint-filled bottles that hurt no one — relative harmony compared with last year, when Ardoyne rioters wounded 100 police, as well as paramedics and journalists, with grenades and Molotov cocktails.

This mild Twelfth coincides with a major effort by the British and Irish governments to revive a Catholic-Protestant administration, the central goal of the province's U.S.-brokered 1998 peace deal. They have set a Nov. 24 deadline for agreement or a final admission of defeat.

Sinn Fein, which represents most Catholics, says it wants to work with Paisley's Democratic Unionist Party and has been on its best behavior in the past year in hopes of promoting a deal with the anti-Catholic evangelist. The IRA has disarmed and pledged that its 1997 cease-fire is permanent.

But Paisley told an Orange crowd that it wasn't going to happen on his watch.

"Compromise, accommodation and the least surrender are the road to final, irrevocable disaster!" said Paisley, 80, who for four decades has been the most strident advocate for Northern Ireland's political union with Britain.

"And no unionist who is a unionist will go into partnership with IRA-Sinn Fein!" Paisley said, shouting each line. "They are not fit to be in partnership with decent people! They are not fit to be in the government of Northern Ireland! And it will be over our dead bodies that they'll ever get there!"

Catholic leaders denounced Paisley's message as hopelessly negative.

"This rant by Paisley — and there is no other name for it — is the politics of the roadblock once again," said Sean Farren of the Social Democratic and Labour Party, Sinn Fein's moderate rival for Catholic votes.

The Twelfth is never a harmonious day but, by recent standards, Wednesday marked a high point in avoiding vandalism and violence.

Suspected Catholic arsonists destroyed a rural Orange hall northwest of Belfast. To ease tensions, Sinn Fein called off a planned protest against a brief Orange parade in a nearby village.

In the divided town of Maghera, Sinn Fein supporters blocked the route of another Orange parade. Riot police lined up to force the illegal mob off the street, but local Protestant leaders volunteered to shorten their parade route away from the mob.

In Northern Ireland's second-largest city of Londonderry, a car was hijacked and set ablaze as Catholic youths threw Molotov cocktails at police armored vehicles. No injuries were reported.

Most attention focused on a single Irish flag placed on top of a bonfire. Spraypainted in black letters on the flag was a vulgar message mocking Michael McIlveen, the most recent victim of Northern Ireland's intercommunal hatreds. McIlveen, 15, had been chased and clubbed to death May 8 by Protestant teenagers in Paisley's power base of Ballymena, northwest of Belfast.

Photographs of the flag atop the bonfire were featured on news broadcasts and newspaper front pages.