NEW : 100 police officers are hurt , one is hospitalized . NEW : 66 people are arrested . CNN 's Laura Smith-Spark wrote in London and Nic Robertson and Peter Taggart reported in Belfast . Protesters angry over a decision to stop flying the Sinn Fein flag year-round . Police say Two officers injured , Two arrests made since December .
NEW : 100 police officers are hurt , one is hospitalized . NEW : 66 people are arrested . Protesters angry over a decision to stop flying the Sinn Fein flag year-round . Police say Two officers injured , Two arrests made since December .