An incendiary device was found on a bus amid bomb threats made during the State visit of Queen Elizabeth five years ago, a court was told.
Donal Billings (66), from Drumlish in Co Longford, was found guilty last month of the unlawful possession of explosives at Longford railway station car park on May 16, 2011.
He was further found guilty of four offences under the Criminal Law Act of 1976. Billings was convicted of making a false report on May 16, 2011, that bombs had been placed at Busaras, the central bus station in Dublin, and at Sinn Fein's headquarters.
He was also convicted of making false reports on May 18 that two mortars were set for Dublin Castle, and on May 20 that two bombs had been placed in the toilets at Cork Airport.
Yesterday, a Garda detective told Dublin's Special Criminal Court how a caller said that there was a bomb on a Dublin-bound Corduff Travel passenger bus, a second bomb on a bus at Busaras and a third bomb at Sinn Fein headquarters in Dublin.
The Corduff Travel bus was stopped on Station Road, Maynooth, and searched by gardai, who found a suspicious object in the luggage compartment.
The device, a combination of gunpowder and a two-litre bottle containing petrol, had the potential for "great destruction", the court heard.
Gardai also searched the Sinn Fein offices and the other bus. Nothing was found. A further phone call was made on May 18, threatening two mortars were set at Dublin Castle - coinciding with a State banquet for the Queen. The caller said: "This is for the Queen of blood and war of Iraq."
Gardai traced the shop where the SIM card used to make the calls was bought. They also used CCTV to identify Billings as a suspect.
He was remanded in custody until December 15, when he will be sentenced.