Armed robbers have ambushed a Saudi prince's diplomatic convoy in Paris, raiding a Mercedes for valuables then torching and abandoning the vehicle, police and prosecutors said.

Handguns were flashed but no shots were fired last night's attack by five to eight assailants, the Paris prosecutor's office said. No injuries or arrests were reported.

Rocco Contento, of the SGP Paris police union, said that the car had 250,000 euro (£200,000) in cash and official embassy documents, and that the assailants were well-informed about the itinerary of the vehicle.

The Paris prosecutor's office the car carried "things of value", but would not confirm the theft of cash or documents.

The Mercedes car, with a driver and two passengers, was heading for the city's Le Bourget airport to handle paperwork for the departing prince, according to the prosecutor's office.

Le Bourget is often used for high-level visitors taking private jets to Paris.

French officials refused to name the prince, who has since left the country for an unidentified destination.

The burned shell of the stolen car was later found near the attack site in northern Paris along with another car, apparently belonging to the assailants, according to the prosecutor's office.

The Saudi Embassy could not be reached for comment.

The French foreign ministry called the attack, coming at the height of tourist season in the French capital, "unacceptable". An investigation was opened for armed robbery in an organised gang.