This is the first time a rocket launcher has been found in a paramilitaries' arms cache

They have also said there are indications that hardline republicans are finding support from new young recruits.

Monday's weapons find includes a shoulder-held RPG-18 launcher which fires armour-piercing rocket propelled grenades.

Such a weapon has not been seen before in Ireland and is said to be more powerful that the old RPG-7 used in the past by the Provisional IRA.

There was also bomb-making equipment which included 3kg of Semtex plastic explosive, 36 detonators and a small quantity of bullets.

They were discovered in a hayshed at Gormanstown, County Meath owned by one of seven men charged in the republic last week in connection with another arms find in the same area.

Underground range

In that raid, an underground shooting range being used by alleged dissident republicans was discovered and a small quantity of arms was seized.

Ballistic teams from the Garda (Irish police) are expected to examine them.

The police officer in charge of the searches later said the material was believed to belong to the Real IRA, the dissident republican terror group which bombed Omagh, Co Tyrone, 15 months ago with the loss of 29 lives.

The hard-line dissident republicans are opposed to the Northern Ireland peace process.

Chief superintendent Michael Finnegan, head of the Garda Siochana's Meath/Louth division, said his team was satisfied there was a direct link between the latest discovery and the finds last week.

Find is 'worrying'

"Any find of this significance is a worry, of course," he said.

"Our drive against those dissident republicans will continue and will be enhanced as a result of recent finds in this area."

Armed members of the force's Special Branch as well as the crack Emergency Response Unit and Air Support Unit were involved in the searches along with uniformed officers.

Mr Finnegan said there were indications that the hardline republicans were finding support from new young recruits as well as disgruntled members of other organisations on ceasefire like the Provisional IRA.

He said: "It goes across a wide spectrum of the community. "On Wednesday night when the bunker was found there were three very young people connected, one of them 14 years of age.

"There are people who have been known to us in the past also involved with the Real IRA at the moment."

Sir Ronnie Flanagan: Praise for Garda success.

In Northern Ireland, Secretary of State Peter Mandelson and the Chief Constable, Sir Ronnie Flanagan, both praised the latest find by the Gardai.

They made their comments as they went into a meeting at RUC headquarters in Belfast.