Eco-activists from Just Stop Oil have infiltrated London's National Gallery and taped themselves to a painting by English landscape painter John Constable.
A video posted on Twitter shows a young man and woman staging their protest against the continued use of fossil fuels before security forces evacuated the hall.
The two students, dressed in "Just Stop Oil" t-shirts, climbed behind the cordon in front of the romantic work of art, completed in 1821, which depicts a eponymous hay cart in rural Suffolk.
They then covered the oil painting with their own new version of the scenery: an apocalyptic vision of devastated nature under a sky dotted with airplanes.
After sticking their hands to the frame of the work, they expressed their motivation, partly to the applause of the students present in the hall: pictures like this are cultural heritage.
But what sense does art have if billions of people are threatened by the consequences of climate change?
The hall was evacuated and the two students were arrested on suspicion of damage to property.
Constable's "hay cart" is said to have sustained minor damage to the painting's frame and varnish, which apparently could be repaired immediately.
The latest coup by "Just Stop Oil" is the fifth within a few days.
At the Silverstone Grand Prix at the weekend, activists from the group invaded the circuit and settled for a sit-in.
Racing driver Lewis Hamilton then expressed sympathy for the protests.
Earlier in Glasgow, members of the protest group had glued themselves to Horatio McCulloch's 1860 painting My Heart's in the Highlands at Kelvingrove Gallery, to the frame of William Turner's 1809 Thomson's Aeolian Harp at Manchester Art Gallery and at the London's Courtauld Gallery recalls a painting by Vincent Van Gogh from 1889 showing peach blossoms in Provence.