While the initial estimate for the security operation around the visits of US president Barack Obama and Queen Elizabeth was €20 million, the cost increased to €36 million because serious security threats arose during the queen’s visit.
Hundreds of rioters clashed with gardaí for almost three hours in Dublin city centre on the first day of the visit, throwing fireworks, bottles and bricks.
The following night gardaí were involved in a stand-off with a crowd of several hundred. They included representatives of Republican Sinn Féin and the 32 County Sovereignty Movement. Pipe bombs were also left at locations in the city.