The introduction of internment was not a closely guarded secret , with newspaper editorials appearing and discussion on television . The IRA went underground or fled across the border . As a result , fewer than 100 arrested were from the IRA . By this stage , support for NICRA began to wane , however NICRA continued to organise anti-internment marches . In Derry on 30 January 1972 NICRA took part in a mass anti-internment march which had also been banned . Fourteen unarmed demonstrators were shot and killed by British troops during the march , and it became known as Bloody Sunday
Bloody Sunday
Bloody Sunday (1972)
Northern Ireland Civil Rights Association