F1 and the FIA have confirmed that "several people" made their way onto the Silverstone Circuit shortly after the British Grand Prix began.
It came during a red flag period that was triggered by a huge Turn 1 accident involving Alfa Romeo driver Zhou Guanyu, who has been taken to the Medical Centre for checks.
Northamptonshire Police stated earlier this week that they had received "credible intelligence" of a protest being planned, with those fears seemingly being realised.
F1 and FIA issue statement over protestors
Images circulating on social media showed apparent protestors making their way onto the track, with marshals acting swiftly to remove them.
"We can confirm that after the red flag, several people attempted to enter the track," read a statement from F1 and the FIA.
"These people were immediately removed and the matter is now being dealt with by the local authorities."
The race is due to restart at 15:56 local time.
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