By politics.co.uk staff
Dublin has shipped in water cannons from Northern Ireland ahead of the Queen's visit later this month.
Authorities are on a high state of alert after the murder of Catholic policeman Ronan Kerr and a Real IRA rally in Londonderry protesting against the monarch's visit.
"We've seen very menacing threats coming from these groups in recent weeks," Irish foreign minister Eamon Gilmore told RTE radio.
"The government is concerned about any dissident threats there are, and the security arrangements are very strong arrangements."
The Real IRA says the Queen is wanted for war crimes and should not set foot in the country, but security experts are also wary of international terrorist attacks in the wake of Osama bin Laden's death, especially given the upcoming visit to Ireland of Barack Obama.
"The security arrangements would be very tight and comprehensive in any event and the gardai are making sure that everything is in place and the Irish people will be able to give the traditional welcome to both Queen Elizabeth and President Obama," Mr Gilmore added.
The British and Irish governments have a lot riding on the visit - the first of a British monarch since independence - which will take place on May 17th.