The Six Hours of Shanghai has been red-flagged after 18 minutes due to heavy rain.
Cars started round five of the FIA World Endurance Championship under safety car conditions but proceedings stopped as drivers struggled for grip.
Several cars had incidents and near missed, with Thomas Laurent spinning the No. 1 Rebellion Racing R13 Gibson into the tire barriers and Tommy Milner rotating the No. 64 Corvette Racing C7.R without contact at the final corner.
Laurent managed to return the Rebellion to its pit garage, although the team cannot repair the car until the race restarts.
WEC CEO Gerard Neveu said on the global TV feed that the red flag would last for the next hour at least, with the rain set to worsen.
“It was impossible, including behind the safety car, to continue to run on the track, for safety,” said Neveu.
“We have information from the weather forecast team and they are very pessimistic. It is more intense, so clearly, the decision from the race director is the only one we can take.
“It is a shame for the public and the TV viewers, but the safety of the drivers is most important.
“We will pay attention to the evolution of the weather.”