Borussia Dortmund supporters launched tennis balls onto the pitch during the German Cup victory against Stuttgart in protest against inflated ticket prices.
Visiting fans paid up to £55 for some tickets with the cheapest seats costing £30 and standing tickets at a more reasonable £15. Large numbers of the Dortmund contingent refused to take their seats in the first 20 minutes, leaving sections of the stand empty.
The protest follows a similar stand by Liverpool supporters, managed by former Dortmund manager Jurgen Klopp, who staged a walk-out in the 77th minute of the 2-2 draw with Sunderland. The Reds have recently announced some tickets in their new Main Stand extension will be priced at £77.
Dortmund fan Marc Quambusch, a member of the campaign group behind the protest, told the BBC World Service: “Obviously it's not something we want to do, but we feel we have to do it. We don't feel very good about not supporting the team for the first 20 minutes, but it has to be.
“It's always good to see [English] fans protesting against bad conditions and, yes, they have our solidarity,” he said. “I hope it is inspiring other fans to join them and to protest as well. I love English football but it is killing itself.”
Goals from Marco Reus, Pierre-Emerick Aubameyang and Henrikh Mkhitaryan sent Dortmund through to the semi-finals of the competition.Reuse content