The Williams team is working with the fire services and the police to determine the root cause of the fire that broke out after the Spanish Grand Prix.
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 squad confirmed four members of the team were injured in the incident. One was treated and released while the other three were transferred to local hospitals for further treatment.
"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.
Nine F1 teams members were understood to be treated following the fire. Caterham said four of its members had been taken to the medical center 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 were subsequently 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," it said.