Berlin authorities have set up scaffolding around the symbolic Brandenburg Gate in the German capital to remove orange paint applied to the monument by climate activists in September, DPA reported, citing Agerpres.

On Monday, workers were setting up scaffolding to continue the operation to clear the monument in conditions where repeated attempts have so far been unsuccessful.

Last Generation, a climate campaign group, claimed responsibility for spraying this Berlin monument and claimed that the paint was water-soluble and did not damage the stonework.

The claim turned out to be false, and attempts to clean the speakers with hot water under pressure were unsuccessful.

What else are the German authorities going to try to clear the Brandenburg Gate?

The sandstone that covers the monument has a relatively large and porous grain and has absorbed paint and water.

According to Birgit Mehring, director of Berliner Immobilienmanagement (BIM), the company that manages the monument for the municipality, a paste will now be applied, which will first be absorbed and then removed with water.

The process will have to be repeated several times, Mehring said, and it could take several weeks.

The estimated cost of the operation is at least $115,000, and maybe more.

Berlin Finance Minister Stefan Evers said the city would try to recover at least some of the money from Last Generation. A total of 14 people were arrested, probably involved in the painting of the Brandenburg Gate.