Williams working to determine cause of fire, FIA says 31 people treated in total

Williams said the fire, which erupted some 90 minutes after the team had won its first race since 2004, had originated from the fuel area.

The Grove squad confirmed four members of the team were injured in the incident. One has already been released while the other three are now receiving treatment at local hospitals.

"The Williams F1 Team would like to thank all of the teams and the FIA for their support in today's incident," said the team in a statement.

It is so far confirmed only nine members were from F1 teams but other team personnel were understood to be involved.

Caterham said four of its members had been taken to the medical centre for examination, while another Force India mechanic had also suffered from smoke inhalation and was under observation.

Formula 1's ruling body, the FIA, said a total of 31 people were seen by medical staff from the circuit. Seven had been transferred to local hospitals.

"The FIA is collaborating closely with the Spanish authorities investigating this incident and will be providing a further update as soon as more information becomes available," said the FIA.