FRANKFURT, Germany (AP) – Activists have blocked the main entrance to the Frankfurt Motor Show in a protest against what they call the “climate and environment destroyers” of the auto industry.

Hundreds of people wearing white protective suits sat or stood in front of the grounds where the auto show is being held on Sunday morning. The demonstration was organized by an alliance of groups called “Sand im Getriebe” — roughly “spanner in the works.”

The show already attracted a demonstration by thousands on Saturday, many of whom cycled into the city along highways temporarily closed for the occasion. Police put turnout at 15,000, while organizers said 25,000 participated.

Environmental groups say the trend toward bigger and more powerful cars, particularly SUVs, is eating into the fuel efficiency gains of recent decades.