US officials have denied that President Barack Obama's limousine, nicknamed The Beast, got stuck leaving the US embassy in Dublin.
A bang was heard as the car hit a ramp before a bus was parked in front to block the view.
Initial reports said the car involved was "The Beast" - the limousine used to carry the first couple.
But a Secret Service spokesman later said "it was a spare limo".
The vehicle had been "carrying staff and support personnel" when it became stuck on the ramp, the spokesman added.
Personal oxygen supply
The incident happened in front of waving crowds in Ballsbridge, and the president left the building from a different entrance.
President Obama and first lady Michelle Obama were being driven to the Marine One helicopter in order to fly to visit his ancestral home in County Offaly.
A witness said that as it drove out, the car appeared to get its low underbelly caught on a piece of metal sticking up that a gate might lock into.
It was initially reported that the first couple stayed in the car while police officers rushed over to the stricken vehicle, before the pair were switched to another vehicle.
But the Secret Service spokesman said the Obamas had not been in that car.
The Beast, specially built for Mr Obama by General Motors, has reinforced tyres and its own oxygen supply.
There was much interest in the armoured car on Mr Obama's visit to the UK in 2009.
Footage of The Beaststruggling to execute a three-point turn in Downing Streetwas a viral hit.
Mr Obama flew into London late on Monday for a three-day state visit to the UK.
He will visit France and Poland later in the week.