Further violent pro - British protests broke out in Belfast , police say . Nine police officers were injured Friday . The disorder follows a summer of heightened tensions between Northern Ireland 's Catholic and Protestant communities . They pelted officers with petrol bombs , fireworks and bricks , police say . Protests have affected parts of Northern Ireland since a vote on the Union Bill .
Further violent pro - British protests broke out in Belfast , police say . Nine police officers were injured Friday . They pelted officers with petrol bombs , fireworks and bricks , police say . Protests have affected parts of Northern Ireland since a vote on the Union Bill .