LONDON (AP) — A pair of paintings by Dutch master Vincent van Gogh at London’s National Gallery were vandalized Friday when a group of climate activists splattered what appeared to be tomato soup on them, shortly after two other activists were sentenced over a similar attack two years ago.

The paintings from Van Gogh's “Sunflowers” series, which the artist painted in Arles in the south of France, were not damaged thanks to protective glass coverings. The gallery identified the two as its own Sunflowers (1888) and Sunflowers (1889) on loan from the Philadelphia Museum of Art.

The three activists from the Just Stop Oil environmental group involved in the attack were arrested while the paintings were removed, examined, and then returned to their location. The exhibition reopened later Friday, the gallery said.

The group posted a video of the attack on social media, showing three people pouring soup over the paintings. The action was apparently in protests against the sentencing earlier Friday of two other activists from the group, Phoebe Plummer, 23, and Anna Holland, 22.

Plummer was sentenced to two years while Holland received a 20-month sentence for their October 2022 attack on a “Sunflowers” painting. The two women threw tins of tomato soup at the artwork, then knelt down in front of it and glued their hands to the wall beneath it. They were found guilty of criminal damage by a jury in July.

In both attacks — in 2022 and on Friday — the activists wore T-shirts supporting Just Stop Oil. The group has been pushing the British government to halt new oil and gas projects and has staged high-profile stunts, including at major sporting events and on Britain's transport networks.

In Friday's video, one of the unnamed activists said that future generations will regard them as “prisoners of conscience” who were "on the right side of history.”

In the 2022 attack, the gold-colored frame of Van Gogh's painting suffered 10,000 pounds ($13,000) worth of damage. At the time, museum staff had worried the soup could have dripped through and caused immeasurable damage to the painting.

In Friday's sentencing, Judge Christopher Hehir said the artwork could have been “seriously damaged or even destroyed."

Hehir was also the judge in the case against Roger Hallam, the co-founder of Just Stop Oil and Extinction Rebellion, another environmental campaigning group, and had sentenced him to five years.

On Friday, he took aim at Plummer. “You clearly think your beliefs give you the right to commit crimes when you feel like it," he said. "You do not.”

Plummer, who represented herself and who had pleaded guilty, told the hearing that she would accept “with a smile” whatever verdict came her way.

“It is not just myself being sentenced today, or my co-defendants, but the foundations of democracy itself," she said.

Five days after her guilty verdict in July, Plummer was arrested for spraying paint on departure boards at Heathrow Airport.

Lawyer Raj Chada, defending Holland, said the two women checked that the “Sunflowers” was protected by a glass cover before throwing the soup.