Climate activists in Austria attacked a famous painting by artist Gustav Klimt with a black, oily liquid, before one glued themselves to glass protecting the painting's frame.
Members of the group Last Generation Austria tweeted they had targeted the 1915 painting Death And Life at the Leopold Museum in Vienna to protest against their government's use of fossil energies.
After throwing the liquid on the painting, which was not damaged, one activist was pushed away by a museum guard while another glued his hand to the glass over the painting's frame.
The group defended the protest, saying in a tweet that they were protesting against "oil and gas drilling" which they called "a death sentence to society".
In a video of the incident, which the group posted online, one of the activists can be heard shouting: "We have known about the problem for 50 years - we must finally act, otherwise the planet will be broken.
"Stop the fossil fuel destruction. We are racing into a climate hell," he added.
After the attack, police arrived at the museum and the black liquid was quickly cleaned off the glass protecting the painting, Austria Press Agency reported.
Despite thorough controls at the museum's entrance, the activists succeeded in bringing the liquid inside by hiding it in a hot water bottle under their clothes, the agency reported.
The Leopold Museum could not immediately be reached for comment.
The Klimt work is an oil on canvas painting in the Art Nouveau style depicting death on the left side and a group of partially naked, hugging people on the right side. It is one of the latest pieces of art to be targeted by climate activists to draw attention to global warming.
Different activist groups have staged numerous demonstrations in recent months, including blocking streets and throwing mashed potatoes at a Claude Monet painting in Germany.
The British group Just Stop Oil threw tomato soup at Vincent van Gogh's Sunflowers in London's National Gallery last month.
Just Stop Oil activists also glued themselves to the frame of an early copy of Leonardo da Vinci's The Last Supper at London's Royal Academy of Arts, and to John Constable's The Hay Wain in the National Gallery.
