Two climate protesters were arrested on Wednesday after spraying orange corn flour on Stonehenge in an audacious bid to pressure the U.K. government to end the use of fossil fuels.

The climate activist group Just Stop Oil took credit for the bold demonstration, saying in a statement that the next government must “sign up to a legally binding treaty to phase out fossil fuels by 2030.” The general election is set to take place on July 4.

Video posted by the group on social media shows protesters spraying orange corn flour on the stone monoliths with fire extinguishers as others pull them away and yell, “Drop it!”

Wiltshire Police said two people were arrested. The organization identified the two as Niamh Lynch, 21, and Rajan Naidu, 73.

Climate protesters in recent years have resorted to outrageous protest tactics that they say are needed to highlight the absurdity of climate policies aimed merely at incremental progress amid an acute crisis, as well as to break through public indifference on the issue. Activists have glued their hands to the frames or protective glass encasing famous artworks in museums and have even thrown food at them. Organizers said there is no intention of causing permanent damage to the paintings, but gallery directors have told protesters that they “severely underestimate the fragility of these irreplaceable objects.” Similarly, Just Stop Oil said that the orange corn flour used in the Stonehenge protest will wash away in the rain.

Such tactics have drawn intense criticism nevertheless. Many U.K. politicians denounced Wednesday’s action. Prime Minister Rishi Sunak called Just Stop Oil a “disgrace.” Labour Party leader Keir Starmer said the damage to Stonehenge was “outrageous” and called for those responsible to “face the full force of the law.”

Yet Just Stop Oil has threatened to escalate its protest by targeting similar stone structures in Europe in the coming months.

“Failure to commit to defending our communities will mean Just Stop Oil supporters, along with citizens from Austria, Canada, Norway, the Netherlands and Switzerland will join in resistance this summer, if their own Governments do not take meaningful action,” the group said in a statement. “Stone circles can be found in every part of Europe showing how we’ve always cooperated across vast distances — we’re building on that legacy.”