French prosecutors said Tuesday they had opened a terror probe over a blast in Saudi Arabia, which took place on December 30 and targeted a car participating in the Dakar rally, badly wounding its French driver.

A preliminary investigation has been opened, the prosecutors said in a statement, "into multiple attempted killings in connection with a terrorist group."

According to the statement, all five occupants of the car, including the driver, were French nationals.

The national anti-terror prosecutors provided no further details over the Jeddah blast, which led driver Philippe Boutron to require surgery in the kingdom for serious leg injuries before returning to his home country.

Organizers said the incident was not related to racing, while the Saudi authorities indicated there had been no criminal suspicion over the explosion.

The French foreign ministry then updated its advice on KSA, contradicting comments about the incident made by both Riyadh and the organizers of the rally.

"An appeal for maximum alertness -- security risk," it said on its website after the blast.

"An investigation by Saudi authorities is underway to determine the cause of this explosion. The possibility of a criminal act has not been ruled out," it added. 

The final stage of this year's edition of the Dakar rally - known as the Dakar 2022 - is to take place on January 14.