MADRID/DUBAI (REUTERS) - Spanish authorities evacuated all passengers and crew from a flight bound for Riyadh at Madrid's Barajas international airport on Thursday (Feb 4) after a bomb threat, which the airline later said was a hoax.

The Saudi Arabian Airlines (Saudia) flight was grounded before take off after the pilot noticed a note with a bomb threat onboard, Spain's interior minister, Jose Fernandez Diaz, said in parliament.

A spokesman for Saudia said the threat was a false alarm and the airline was taking all the necessary precautionary formalities. "It's just another hoax that all airlines are subjected to," he said.

Spain's airport operator Aena said they had downgraded the alarm from general to local, meaning the alert would not affect other flights and the airport would continue operating as normal.

Flight SVA 226, which had been due to leave just before 1000 GMT with 112 passengers and crew and was seen at the airport with the inflatable ramps extended and fire and security services nearby, has since been isolated while the investigation is carried out.

El Pais newspaper said the note, with "bomb threat" written in English, was attached to a baggage compartment in the plane with a knife.