Formula Two racers Theo Pourchaire and Enzo Fittipaldi were airlifted to hospital on Sunday after a start-line crash in the Saudi Arabian round of the Formula One feeder series.
Both drivers were conscious and were extricated from their cars by medical crews, governing body the FIA said in a statement.
"The drivers were immediately attended to by emergency and medical crews. Both have been transferred by ambulance and helicopter to King Fahad Armed Forces Hospital, Jeddah," added the statement.
The crash between Frenchman Pourchaire, who races for ART, and Fittipaldi, who is the grandson of Brazilian Formula One double world champion Emerson Fittipaldi and races for the Charouz team, brought out the red flags on the first lap.
The race got underway with a rolling restart but was suspended shortly afterwards, following a brief safety car period, due to another accident involving Briton Olli Caldwell and Brazilian Guilherme Samaia. Both drivers walked away unhurt.
Formula Two was being run as a support event to the inaugural Saudi Arabian Formula One Grand Prix this weekend at the Jeddah Corniche street track.
Its 6.1-km layout , the second fastest on the calendar after Italian 'Temple of Speed' Monza, is made up of mainly flat-out blasts and blind sweeps hemmed in by walls and has raised safety concerns.
(Reporting by Abhishek Takle; editing by Clare Fallon)