A night of rioting by Catholic militants in Northern Ireland wounded 22 police officers, hours before mass Protestant parades Tuesday that are an annual test of the British territory's peace process.
Lines of riot police prevented masked Catholic men and youths from attacking nearby Protestant districts in several parts of Belfast overnight.
Officers in helmets, shields and flameproof suits suffered hours-long barrages of bottles, bricks, stones and about 40 Molotov cocktails. They reported firing 51 British-style plastic bullets _ blunt-nosed cylinders designed to deal punishing blows to rioters _ and dousing the mobs with blasts from water cannons.
During the worst clashes in the Broadway district of Catholic west Belfast, rioters hijacked a bus and tried to drive it into police lines. But the driver lost control and crashed it.
Sinn Fein deputy leader Martin McGuinness, a former Irish Republican Army commander who today is the senior Catholic in Northern Ireland's unity government, appealed to the rioters not to repeat their performance at the end of Tuesday's parades by the Orange Order.
The Orange Order, a conservative Protestant brotherhood that marches under banners depicting the British crown on an open Bible, stages parades each July 12 in commemoration of a 17th-century military victory over Irish Catholics. "The Twelfth" is an official Northern Ireland holiday that many Catholics despise, and the event often raises community tensions to breaking point.
McGuinness and police chiefs warned of likely violence Tuesday night at the worst Belfast flashpoint: Ardoyne, a traditional IRA stronghold where splinter groups in recent years have mounted anti-Orange attacks as a small Protestant parade passes the area. The dissidents oppose the IRA's 2005 decision to disarm and renounce violence, a key Protestant condition for Sinn Fein to enter Northern Ireland's government.
McGuinness and other Sinn Fein officials described the rioters as drunken hooligans who had gone out of their way to confront police at key sectarian fault lines of Belfast.
"The people who found themselves at Broadway last night had traveled from different parts of Belfast to inflict pain and hurt on the local community and attack the police," said McGuinness, who in his IRA days once encouraged such events.
During the violence, firefighters came under attack in both Protestant and Catholic districts. The firefighters were on high alert because "The Twelfth" traditionally begins with the lighting of massive _ and often dangerously unwieldy _ bonfires in Protestant areas at midnight. Firefighters said they responded to 180 emergency calls overnight, 65 percent more than last year, during which one fire engine was vandalized and two firemen were injured by thrown objects.
British Army experts also dismantled a fake car bomb abandoned in a Protestant district of north Belfast near Ardoyne. The alert forced scores of Protestant families to evacuate their homes overnight.
Later Tuesday, police received warnings of multiple bombs on a street in the town of Lurgan. Bomb disposal engineers used remote-controlled robots to blast several suspicious abandoned objects in the area but no bombs were found.
Tuesday's street mayhem followed weeks of similar flare-ups in working-class parts of Belfast and nearby suburbs that have left scores of police injured, none critically. Last week, Protestants rioted in one suburb after police removed British and sectarian flags from posts outside the area's lone Catholic church.
Northern Ireland remains a deeply divided society despite the broad success of its two-decade-old peace process. The long negotiations achieved a Catholic-Protestant government, British Army withdrawals and disarmament by most illegal paramilitary groups _ but did nothing to bring down more than 40 Belfast barricades called "peace lines" that still separate Irish Catholic and British Protestant turf.