Police in Ireland have discovered an improvised explosive device on a bus near the capital, Dublin, on the day Britain's Queen
Elizabeth II is due to arrive in the country on an historic visit, DPA reported.
An army spokesman said the "viable" device was found in the luggage compartment of a bus on the outskirts of Maynooth, in County Kildare, near Dublin.
A controlled explosion was carried out and the device made safe by the Irish army in the early hours of Tuesday, he said.
A massive security operation is under way in Dublin, where the queen is due to arrive later Tuesday. The 85-year-old is the first British monarch to visit the Republic of Ireland since it gained independence from Britain in 1921.
On Monday, police in central London were placed on high alert following a bomb threat from dissidents of an Irish Republican splinter group.
No device was found, but the area in the vicinity of Buckingham Palace was closed off for most of the day. The unspecific threat did not give a time or location for any possible attack, Scotland Yard said.