Officers set up checkpoints and diversions as far as 20 miles outside Armagh as the monarch prepared to visit St Patrick's Cathedral in the city.

Police with specially-trained dogs checked buildings, and roads within the security ring were combed for suspect devices.

Vehicles belonging to guests and the media being shepherded through the Drumadd army barracks in the area were also checked.

Police yesterday warned royal fans to stay away from Armagh due to the diversions.

Those allowed to pass had to leave their vehicles at the army barracks and were taken by bus to the Anglican cathedral for the historic function.

The service at the Church of Ireland cathedral marks the finale of a three-day visit to Northern Ireland by the head of state and Prince Philip.

Maundy money will be dished out by the monarch to deserving OAPs as a symbol of the giving of alms and Christ's washing of the apostles' feet on Holy Thursday.

A total of 164 pensioners - 82 men and 82 women, reflecting the Queen's age of 82 - will receive specially minted coins to a total of £5.50 in a red purse and 82 pence in a white purse.

It will be the first time the Queen has carried out the ceremony outside England and Wales.

Catholic primate cardinal Sean Brady will join Archbishop Alan Harper and other church leaders for the cross-community service.