The second practice session at the Suzuka racetrack was stopped four times by red flags, twice because of small grass fires apparently started by sparks emitted from the back of the cars as they passed. They were quickly extinguished.
"While we continue to look into the fires that occurred during FP2, our focus before tomorrow will be on taking preemptive measures," the governing FIA said in a statement.
"The grass has been cut as short as possible, and loose, dried grass has been removed from affected areas. Prior to tomorrow's sessions, the grass will be dampened, and specific response teams will be stationed around the track."
Practice at last year's Chinese Grand Prix in Shanghai was also interrupted by a red flag when a small grass fire broke out at trackside.
The third round of the Formula One season continues on Saturday with another practice session and qualifying for Sunday's race.