The Mayor of Rome Roberto Gualtieri condemned the protest in a statement on Facebook and said the activists severely damaged the fountain which will now have to undergo a "complex cleanining operation that will cost a lot of work."

"This is not the right way to conduct a battle for the environment and against climate change," Gualtieri said on Facebook.

"Such gestures are completely wrong and damaging, because they risk damaging precious common goods such as our monuments, and force public administrations into very expensive and environmentally impactful restoration interventions. So they are completely counterproductive."