Thousands of police are deployed in Belfast to prevent possible outbreaks of violence . The parade marks the centenary of the signing of the pro-union Ulster Covenant . Up to 30,000 people are expected to take part in the march . - March 24 :
Thousands of police are deployed in Belfast to prevent possible outbreaks of violence . The parade marks the centenary of the signing of the pro-union Ulster Covenant . Up to 30,000 people are expected to take part in the march . Tensions have been high this summer between Catholics and Protestants in the city .