SILVERSTONE, England (AP)Zhou Guanyu was involved in a frightening first-lap crash Sunday that brought the British Grand Prix to an immediate halt as safety crews attended to the only Chinese driver in Formula One.

Zhou’s car slid upside-down across the gravel and his Alfa Romeo seemed to be wedged between fencing and a tire barrier at the first corner. The race was red-flagged and George Russell, one of the drivers involved in the crash, sprinted from his car to the tire barrier to check on Zhou.

”Zhou is conscious, he is talking, there are no fractures,” Alfa Romeo radioed Zhou’s teammate Valtteri Bottas.

The FIA said Zhou is under observation in the medical center.

Alex Albon of Williams was also taken to the medical center and then his team said he’d been transferred by helicopter to Coventry Hospital for a precautionary check. Albon had spun into the pit wall after being struck by Sebastian Vettel from behind as drivers tried to avoid the incident involving Zhou.

Russell appeared to be hit from behind at the start and was knocked into Zhou, whose car went flying across a gravel trap and over a tire wall into the retaining fence. The car was skidding on the ”halo” which protects the driver’s head, then went airborne. It was stuck between the tire wall and the fence, delaying efforts to extricate Zhou.

Russell, who ran from his car to help Zhou, called it ”one of the scariest crashes I’ve ever seen.”

Russell was declared out of the race by the FIA because his Mercedes was loaded onto a truck to be taken back to pit lane while he was checking on Zhou. Mercedes protested the call, but the FIA did not budge.

The drivers returned to the pits to await a restart.

After the race was stopped, ”several people attempted to enter the track,” F1 said in a statement. ”These people were immediately removed and the matter is now being dealt with by the local authorities.”

Local police had warned Friday spectators might enter the track as part of a protest. An environmental group called Just Stop Oil said that five of its activists had entered the track and sat down.

The group also tried to disrupt some Premier League soccer games in England in recent months. Just Stop Oil named one of those on the track at Silverstone on Sunday as a protestor who also attached himself to a goal post at a game in March between Everton and Newcastle.

The ”halo” device around the cockpit played a prominent role earlier Sunday in a Formula Two race at Silverstone when Dennis Hauger’s car landed on top of rival Roy Nissany’s car. The incident was reminiscent of a crash in F1 involving Max Verstappen and Lewis Hamilton at the Italian Grand Prix last year.

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