Monterrey (California): Two Spanish racers were killed in a chain-reaction crash on the first lap of a World Superbike race in California.

Police spokesman Cmdr. John Thornburg on Monday confirmed the deaths in Sunday's crash at Mazda Raceway at Laguna Seca.

A local newspaper reported that thunderstorms had drenched the track ahead of the race.

Race organisers MotoAmerica identified the dead as 35-year-old Bernat Martinez and 27-year-old Daniel Rivas Fernandez. Both were taken to hospitals, where they later died.

Thornburg said his office is not investigating the crash, which appears to be an accident.

MotoAmerica sent condolences to the families in a statement released by the organization.