Seven protestors with a banner demanding the resignation of Stuttgart's mayor had temporarily halted demolition work on the north wing of the station by climbing onto the roof late Wednesday.
The activists said they would come down from the building if German Transport Minister Peter Ramsauer would agree to suspend construction. But the police officers surprised them and they were quickly removed from the premises without incident.
After several thousand people gathered on Wednesday night to protest the controversial partial demolition of the station, the police said the opposition to the massive rail project was growing more aggressive.
Demonstration organisers said some 12,000 demonstrators showed up to demand an end to the €4.5-billion project Stuttgart 21, which aims to transform the city into an important European railway crossroads.
The police said in a statement that they counted about 5,000 protestors, noting that that the group became increasingly agitated as construction workers began to tear down the northern wing of the station. The authorities said the demonstration had little of the peaceful character of past protests, as people even blocked rescue vehicles from reaching an emergency situation.
Some 200 activists also blocked streets in the city centre and erected blockades out of rubbish bins on the B14 motorway until late in the evening, police said.
Stuttgart police chief Siegried Stumpf dismissed the protests as having nothing to do with civil disobedience.
“Those who block rescue workers are acting criminally,” he said in a statement.
Spokesperson for the protest action, Gangolf Stocker, called for activists to form a human chain around the Stuttgart city hall on Friday evening, preceded by a constant block of the construction site entrance so there would be “nothing more in, and nothing more out.”
According to rail industry expert Christian Böttger in an interview with daily Frankfurter Rundschau, halting the project would cost between €400 million and €500 million, and not €1.4 billion as recently suggested by Stuttgart 21 spokesperson Wolfgang Drexler.
Stuttgart architecture professor Frei Otto, who initially advised architecture firm Ingenhoven, Overdiek and Partner's winning design entry, pulled out of the project a year ago due to safety concerns and he has warned that the project should be stopped. Partner in the firm Christoph Ingenhoven rejected the notion, however, telling daily Rheinische Post this would be “near to fearmongering.”