Marcel Kittel of the Giant Shimano team (left) on his way to winning stage 3 of the Giro d'Italia 2014 into Dublin. Inset: Finnstown House where the bomb was discovered

ANTI-terrorist detectives seized a massive car bomb in Dublin which was primed and ready to be detonated.

The car containing the milk churn bomb was discovered by gardai in the car park of the Finnstown Country House hotel in Lucan, Co Dublin.

Sources revealed that it contained 50lb of explosives made from fertiliser, and was armed and ready for use with a timer attached.

While the intended target remained unclear, the bomb was seized just hours before the culmination of the high profile Giro d'Italia.

The cycling race brought hundreds of thousands of people to the streets of Dublin yesterday, and the event is broadcast to 125 million households worldwide.

"This was a deadly, full-size bomb which had been wired up and ready for imminent use. If it had gone off it would have caused total devastation," a source said.

The Irish Independent understands that dissident republicans are suspected of transporting the device from Belfast to Dublin in recent days. It is believed the device was going to be moved from the Lucan car park to its intended target.

Security sources say that the device, made safe by an Army Bomb Squad, would have caused carnage if it had exploded. It is understood that it was fitted with a Timer Power Unit, a hallmark of all major IRA bombs. Also known as a "safe to arm" switch, the TPU can be set to detonate at a given time, which can range from a few hours to several days or even months after it is set.

It is understood that a Dublin man who was later arrested has close links to the Real IRA.

The man is from the inner city and was an associate of murdered RIRA boss Alan Ryan. Gardai located the device after receiving a tip-off, and a major security operation was launched.

Hundreds of guests – many of whom had been attending a wedding – were left stranded outside the luxury Finnstown Country House Hotel overnight after the massive bomb was discovered in the car park.

The alarm was raised at about 8.40pm on Saturday night in a 999 call to gardai. Gardai and the army's Explosive Ordinance Disposal unit arrived a short time afterwards and ordered that the hotel be evacuated at around 10.30pm.

The guests were forced to remain outside the premises until after the viable device was declared safe at 3.45am yesterday. It was found in a car with a Northern Ireland registration plate in one of the car parks on the premises of the 18th century hotel.

A man in his 50s was arrested later yesterday and was detained at Lucan garda station under Section 30 of the Offences Against the State Act, 1939. He can be detained for up to 72 hours.

Hotel general manager Gavin Creaton confirmed there was a "full house" at the time the alarm was raised.

Mr Creaton said: "We became aware of the device sometime after 10pm on Saturday night. We co-operated fully with the gardai and had the entire hotel evacuated while the authorities dealt with the situation."

A security source revealed that dissident Republicans may have been planning an attack, in the hope that it would be blamed on another terrorist group.

"It cannot be ruled out that it may have been intended to disrupt the Giro d'Italia race. This would be a very dramatic escalation in the activities of dissident republicans," he added.

Irish Independent