Northamptonshire police arrested on Sunday at Silverstone seven people belonging to the Just Stop Oil climate activist group who had gained access to the track and staged a protest.
The demonstrators had jumped the barrier near the bridge on Wellington Straight during the race's opening lap and were walking along the side of the track as the cars appeared in sight.
Fortunately, the race had been red flagged moments earlier due to the massive start-line crash involving Alfa Romeo's Zhou Guanyu.
The individuals nevertheless staged their protest and sat on the track after all the cars had gone by, before they were dragged off and held by marshals until the arrival of the police.
On Friday, Northamptonshire police had received "credible intelligence" warning of a possible protest.
Event commander and chief inspector Tom Thompson said: "I'm really disappointed that this group of people ignored our warnings prior to race day and made the incredibly dangerous decision to enter the track."
"We offered to facilitate a peaceful event at the circuit, but they instead chose to put the lives of the drivers, marshals and volunteers at risk.
"It is incredibly disappointing that anyone would make the decision to do this."
By chance, the risky situation was partially defused by the race's red flag, but F1 CEO Stefano Domenicali hit out at the protesters for their "completely irresponsible and dangerous actions" that "put lives in danger".
"Everyone has the right to speak out on issues, but no one has the right to put lives in danger," he added.
"The actions of a small group of people today were completely irresponsible and dangerous.
"We thank the police for their great work, and we shouldn't be complacent about the risk this posed to the safety of the drivers, marshals, fans and the individuals themselves."
In the post-race press conference, seven-time world champion Lewis Hamilton raised a few eyebrows when he appeared to offer his support to the protesters.
"I love that people are fighting for the planet and we need more people like them," said Hamilton who finished third on Sunday's race.
Mercedes later released a statement in which it clarified Hamilton's words: "Lewis was endorsing their right to protest but not the method that they chose, which compromised their safety and that of others".
Ferrari's Charles Leclerc was running fourth just behind Hamilton on the opening lap when he noticed a group of individuals wearing orange T-shirts walking on the side of the track.
"I thought they were marshals, I think because they were in orange," said the Monegasque. "Then I checked and there were written things there that I didn't read, because we were going too quick."
Alpine's Esteban Ocon noted that disruptive incidents at public events are becoming more and more frequent.
"At the moment, we are seeing that a bit too much - the French Open, that's one of them that we saw. There's quite a lot in France that I saw as well, on the road, on the motorway," he said.
"I mean, I understand some ideas, but this is risking their life. And that can't happen."
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