By Ian Graham
BELFAST, July 15 (Reuters) - Rioters threw petrol bombs, bricks, bottles and fireworks at police in a third night of violence in Northern Ireland around traditional Protestant marches, wounding one officer early on Monday.
Protesters built a burning barricade across one road and burned out one car during the clashes that first flared on Friday following a dispute over a marching route.
Thousands of pro-British Protestants march every summer, a regular flashpoint for sectarian violence as Catholics, many of whom favour unification with Ireland, see the parades as a provocation.
A 1998 peace deal mostly ended decades of sectarian strife in the British province but trouble still breaks out, particularly around the Orange parades which mark a 1690 Protestant victory over a Catholic king.
Police said they had brought hundreds of reinforcements from Britain to cope with any more violence.
Both the Protestant Orange Order, which organises the marches, and the devolved government, called for calm.
"It's very important that cool heads prevail in these circumstances and I hope people will obey the announcement and statement by the Orange Institution that people should desist from violence," said Peter Robinson, who heads the government.
Protestant marchers, unhappy because authorities ruled they could not walk along a stretch of road that divides the two communities, started throwing bricks and bottles at police on Friday.
The force responded with water cannon and rubber bullets.
Forty-four police officers have been wounded over the weekend and 49 people arrested, including one aged 10.
Special court sittings were held on Sunday to deal with 10 of those charged and most were remanded in custody. (Editing by Sam Cage and Andrew Heavens)