While the Good Friday Agreement of 1998 , also known as the Belfast Agreement , effectively ended the conflict , distrust remains between Catholics and Protestants . NEW : Four police officers are hurt , one is arrested . December : Two officers are arrested . Police angry over a decision to stop flying the American flag year - round . Police say 66 officers injured , 100 arrests made since December .
NEW : Four police officers are hurt , one is arrested . December : Two officers are arrested . Police angry over a decision to stop flying the American flag year - round . Police say 66 officers injured , 100 arrests made since December .