A second night of riots erupted in Northern Ireland's capital, Belfast, after police blocked Irish nationalists from confronting Protestant loyalists after an annual march Tuesday. The riots took place in the flashpoint area of Ardoyne, in north Belfast.

Police used water cannons and fired plastic bullets against the rioters, who threw gasoline bombs, bricks and fireworks at them.

Monday, 22 police officers were injured in rioting leading up to the divisive annual holiday known as “The Twelfth,” marking the Protestant victory in the Battle of Boyne in 1690. Tens of thousands of Protestants march in Northern Ireland each year to commemorate King William's victory over the Catholic King James, rival claimants of the English, Scottish and Irish thrones

Earlier this month six Northern Ireland police officers were injured in similar rioting in Belfast following a Protestant march.

Protestant loyalists in Northern Ireland want to remain part of the United Kingdom, while Catholic Republicans want to break free of British rule and join the Irish Republic. The 1998 “Good Friday” peace accords have largely ended a 30 year cycle of sectarian bombings and shootings in the province and led to the creation of a power-sharing Northern Irish Assembly.