German clubs who cannot contain unruly fans should be punished by playing matches behind closed doors, Germany's police union said.

Dozens of Hertha Berlin fans stormed the Olympic stadium pitch after a 2-1 home defeat against Nuremberg on Saturday left the capital side anchored to the bottom of the Bundesliga.

The supporters, some armed with steel bars, demolished team benches and advertising panels, chasing stewards around the pitch as players and coaches fled to the changing rooms.

Four officers were slightly injured and some 30 people were detained as police in riot gear restored order.

"There needs to be more drastic measures and that means football without spectators," German police officers' union chief Rainer Wendt said.

"I was not at the stadium but the television pictures clearly show that the officers who were there were completely overwhelmed."

Wendt said tough measures were necessary so that "troublemakers really feel that they are damaging their clubs."

Wendt is not the only advocate of cracking down hard with German league (DFL) chief Reinhard Rauball saying he fully supported "tough punishment."

"The DFL and the clubs will not tolerate violent fans. There will be a unified line with the soccer federation (DFB) against those rioting fans," Rauball said in a statement.

Crowd trouble in German stadiums is relatively rare, with clubs more often fined for fans lighting flares in the stands.