Demonstrators have disrupted the Champions League Group E encounter between Basel and Schalke after unfurling a banner from the roof of St Jakob's Park.
In the fourth minute, play came to a halt as a banner reading "Don't Foul the Arctic" became visible from the top of the stand aimed at Schalke's sponsors, the Russian company Gazprom.
Referee Antonio Undiano stopped the match briefly as players and spectators, including UEFA president Michel Platini, looked on in bemusement.
The protest comes after 30 Greenpeace activists were arrested for scaling an Arctic oil platform belonging to Gazprom.
