Two nights of clashes between Protestants and Catholics in Northern Ireland have left three people injured, in violence that is among the most intense in the province in years.

A photographer working for Britain's Press Association news agency was shot in the leg during the unrest Tuesday night in a small Catholic community near a predominantly Protestant area of east Belfast. Riots Monday night left two people hospitalized with gunshot wounds.

Police say about 400 people were involved in the Tuesday fighting that saw both sides throw stones and gasoline bombs. Police officers in east Belfast struggled to keep the two sides apart.

Police blamed the Ulster Volunteer Force, a paramilitary Protestant group, for starting the riots.

Northern Ireland officials call the two nights of violence the worst outbreak after a long period of quiet. The attacks come at the start of the annual sectarian parade season.

Protestants in Northern Ireland want to remain part of the United Kingdom, while Catholics want to break free of British rule and join Ireland.

The factions signed the Good Friday Peace Accords in 1998, ending nearly 30 years of often deadly violence. Both sides now govern Northern Ireland as part of a power-sharing agreement.