The Japan Times - Environment activists smear paint on Monet work in Stockholm

"Two women around the ages of 25 and 30 were arrested," police said, as the organisation Aterstall Vatmarker (Restore Wetlands) claimed responsibility in an interview with AFP.

The museum told AFP it was "not yet known" if the painting itself had been damaged.

The artwork was "The Artist's Garden at Giverny", painted by French impressionist Claude Monet in 1900.

The painting "is being examined by the museum's curators to see if there has been any damage", the museum said in a statement, while spokeswoman Hanna Tottmar said they hoped to "have more information" on Thursday.

Aterstall Vatmarker posted a video on Facebook where the two women, one a nurse and the other a nursing student, could be seen smearing the paint and gluing their hands to the glass.

The two then shout: "The (climate) situation is acute" and "our health is threatened".

In an interview with AFP, Aterstall Vatmarker spokesperson Helen Wahlgren said a climate catastrophe "is also a health crisis" with "millions of people already dying from the climate disaster".

The organisation said "gorgeous gardens like those in Monet's painting will soon be a distant memory."

Wahlgren accused the Swedish government of not respecting its international climate commitments.

"We should lower our emissions by 31 percent. But our emissions are still increasing. It's outrageous."

The museum said it was "naturally" opposed to actions that risk damaging works of art.

"Cultural heritage has great symbolic value and it is unacceptable to attack or destroy it, regardless of the purpose," acting chief curator Per Hedstrom said.

T.Ikeda--JT