Passengers on a Saudi Airlines flight from Spain to Riyadh were evacuated from their plane Thursday following an unspecified threat that put Madrid airport on high alert, airport authorities said.

“Security forces and rescue services are mobilised. The plane was isolated and passengers evacuated,” a spokeswoman for AENA, the group that manages airports in Spain, told AFP.

An alarm raised at Spanish international airport Barajas after a bomb threat on a flight bound for Riyadh, Saudi Arabia was lowered to local from general, Spanish airport operator Aena said on Thursday.

The alarm does not affect any other flight in and out of the airport, Aena said.

All passengers and crew have been evacuated from the plane, which has been isolated at the airport, the operator added.

Flight SVA 226 returned to Barajas airport after an alert was raised over a bomb threat, the Interior Minister Jose Fernandez Diaz said.

Aena later clarified the plane never took off.