BELFAST, Northern Ireland — Hundreds of police reinforcements from Britain were deployed Saturday in Belfast after Protestant riots over a blocked march left 32 officers, a senior lawmaker and at least 8 rioters injured.

Northern Ireland’s police commander, Chief Constable Matt Baggott, blamed leaders of the Orange Order brotherhood for inciting running street battles in two parts of Belfast that lasted six hours and subsided early Saturday. He called the group’s leaders reckless and said they had had no plan for controlling the crowds they had summoned.

The fraternity’s annual July 12 marches always raise tensions with the Roman Catholic minority here. In each of the previous four years, violence broke out after an Orange parade passed by the mainly Catholic district of Ardoyne in north Belfast.

This year, the British authorities ordered the marchers to avoid the stretch of road nearest Ardoyne, an order that the police enforced by blocking the parade route with seven armored vehicles. Orange leaders took that as a challenge and rallied thousands of supporters to the spot, where some attacked police vehicles and the lines of heavily armored officers behind them.