Two women, aged 20 and 21, appeared in court to face charges of criminal damage after they threw tomato soup at one of Vincent van Gogh's paintings at the National Gallery in London.
A third woman was charged for dousing paint on a sign at the New Scotland Yard headquarters of London's Metropolitan Police.
All three pleaded not guilty to criminal damage during their brief sessions at the Westminster Magistrates' Court.
Why were they arrested?
The women were part of the climate activist group Just Stop Oil that has been demanding the UK government put a stop to new oil and gas projects.
The group has been demonstrating in the British capital for two weeks now, often taking aim at national treasures.
On Friday, the two women threw tomato soup from Heinz cans onto Vincent van Gogh's "Sunflowers," painted in the 1880s. They then glued their hands to the gallery wall.
Prosecutor Ola Oyedepo said the pair did not harm the oil painting thanks to a glass protective case. But damage was caused to the frame, she said.
The painting was cleaned and put back on display by Friday afternoon.
Police said they made some 28 arrests in relation to protests by the group on Friday.