MONTREAL (Reuters) - The Canadian Formula One Grand Prix resumed behind the safety car after a rain delay of more than two hours on Sunday.

Red Bull's world champion Sebastian Vettel was leading, after starting on pole position, when the race was red flagged and cars ordered to park on the starting grid as rain lashed the the Circuit Gilles Villeneuve with just 24 of 70 laps completed.

As drivers climbed back into their cars rain continued fall but officials determined that conditions had improved enough for a restart.

The race is the first run in wet weather this season, making the twisting and challenging layout all the more treacherous.

(Editing by Alan Baldwin)