LONDON (Reuters) - Formula One cars will continue to use titanium skid blocks for the rest of the season after testing stainless steel alternatives to reduce the risk of trackside grass fires.

Second practice at Suzuka in April was stopped four times by red flags, twice because of trackside fires set by sparks from cars.

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.