Angry young men confront police in Northern Ireland on Saturday.<br/> <br />It's not unusual for the annual Protestant Orange Order marches in Belfast to turn violent.<br/> <br />The parades are a regular flashpoint for sectarian clashes.<br/> <br />A high profile peace deal in 1998 largely ended three decades of strife in Northern Ireland.<br/> <br />But Belfast is still riven with religious and nationalist tension between Protestants loyal to the British government and Catholics, many of whom favour reunification with Ireland.<br/> <br />The Protestant Orange Order was angered this year when authorities ruled they couldn't march a stretch of road dividing the two communities - an act seen as provocative by many in the Catholic community.<br/> <br />Police drafted 400 reinforcements from other parts of Britain as they battled Protestants demonstrators into the night.<br/> <br />More than 20 people have been arrested.
