Police say the soup caused some "minor damage to the frame," but that the painting itself is not damaged.
A video shows two protesters in front of the Van Gogh painting on Friday opening two cans of tomato soup before throwing it on the artwork.
People can be heard gasping in the background before someone yells “security.”
One of the protesters then gave a speech shouting, “What is worth more, art or life? Is it worth more than food? Worth more than justice? Are you more concerned about the protection of a painting or the protection of our planet and people?”
The protestor continues by stating that millions of people can’t afford fuel and it’s part of the cost of living crisis.
“Fuel is unaffordable to millions of cold, hungry families. They can’t even afford to heat a tin of soup,” they add.
The group also posted the video on its Facebook page.
People are taking to the comments section to post their reactions, with many condemning the act.
“I’m in total agreement with Just Stop Oil but not this act of vandalism,” one person writes.
“Omg is that the Van Gogh painting? I’m so mortified. This isn’t peaceful protesting,” another comment reads.
Others are standing with the group.
“Great work Just Stop Oil,” a comment reads.
"No worries painting was protected by glass, ok Van Gogh and art work should not be attacked, however respect to these pple who rise up 
," another one says.
Specialist police officers had to un-glue the protesters before they arrested them for criminal damage and aggravated trespassing, according to a press release from London’s Metropolitan Police.
Vincent Van Gogh’s "Sunflowers" painting is one of five renderings of sunflowers by Van Gogh, the others are in museums and galleries across the world, the National Gallery says on its website.
Van Gogh made the paintings in 1888 to decorate his house in Arles before a visit from his friend and artist Paul Gaugin.
