The police commander in Northern Ireland has confirmed that the British Army's secretive surveillance unit is keeping watch on IRA dissidents believed to be plotting a bomb attack or assassination in the run-up to St. Patrick's Day.

Chief Constable Hugh Orde denied in interviews Friday that he tried to keep the deployment of Special Reconnaissance Regiment troops secret. He said they were needed to help monitor Irish Republican Army dissidents who were expected to strike somewhere as leaders of Northern Ireland's Catholic-Protestant government travel to Washington for Ireland's national holiday March 17.

Leaders of Northern Ireland's Irish Catholic minority say the increased use of British troops violates a 2005 decision to withdraw the army from security duties.