Despite the presence of police forces, four activists from ‘Extinction Rebellion Racing’ and ‘Last Generation’ managed to gain access to the opening turn of the track prior to the second race of the weekend.
A marshal who tried to stop the protestors from invading the track was injured in the process, according to a report by dpa referring to a police spokesperson.
Bild further reported that the 47-year-old man suffered bruises and abrasion in the altercation, but was able to leave the hospital later.
The police are investigating three people for bodily harm, while several others are being probed for trespassing. In total, 13 people have been arrested by the local authorities in Nuremberg, Germany.
The activists are understood to have climbed over a safety fence into an area adjacent to the track at 1:15pm, about 15 minutes prior to the start of the race, before storming onto the racetrack in orange safety vests and placards.
One activist poured an orange liquid on the track, which the ‘Last Generation’ claims was oil, while another tried to tie himself to a catch fence on the inside of the track.
However, it took only a few minutes for the police and emergency personnel to arrive at the scene with vehicles, and they were able to quickly overpower the protestors.
The organisers and the police had been expecting a “peaceful protest”, with a bicycle demonstration having been announced for Sunday.
"You can definitely have a different opinion on some things, but for me, it is more than questionable whether you have to express it in this way," ADAC motorsport boss Thomas Voss told German broadcaster ran.de.
"I think it's dangerous. And I feel a bit sorry for the spectators.
"We were prepared, of course, because something had been announced beforehand. That it now comes to such conflict stories, unfortunately, it does not suit us at all."
Members of the police force were not only stationed on the starting grid and the track but also inside the race control - although this is usual for a non-permanent track.
When the track surveillance cameras showed that everything was not going to plan, the race director withdrew and handed over the matter to the police.
Unlike the Formula E race in Berlin or last year’s British Grand Prix, there was no immediate danger as the protests took place 10 minutes before the start of the race.
A decision was also taken to delay the start by 12 minutes as a track cleaning vehicle was required to wipe the liquid dropped by protestors near Turn 1.
However, the ADAC admits that the situation could have been different if the race had gone ahead while the protestors were still on track.
"It's very dangerous," said Voss." I don't want to imagine what would have happened if nobody had noticed and we had gone through with the start."
