In this file photo visitors take pictures of Johannes Vermeer s Girl with a Pearl Earring (approx. 1665) during a preview for the press of the renovated Mauritshuis museum in The Hague, Netherlands, June 20, 2014. AP
Two people glued themselves to the famed painting and adjoining wall, while another threw an unknown substance, but the artwork was behind glass and undamaged, the Mauritshuis said.
Social media images showed activists wearing "Just Stop Oil" T-shirts and saying "how do you feel", while museum visitors shouted "shame" and "you're stupid".
The attack comes after environmental activists poured tomato soup over Dutch artist Vincent van Gogh's "Sunflowers" at the National Gallery in London and smeared mashed potato over a Monet painting in Germany.
"Around 2 pm (1200 GMT) two people glued themselves to the Girl with a Pearl Earring by Johannes Vermeer," the Mauritshuis said in a statement to AFP.
"One person glued his head to the painting, which was behind glass, and the other person glued his hand to the green wall next to the painting. A third person threw an unknown substance at the painting."
The museum added: "We have immediately inspected the painting, which was done by our restorers. Fortunately the painting... was not damaged."
The painting would return on display "as soon as possible".
"Art is defenceless and to try and damage it for whichever cause, we strongly condemn it," the Mauritshuis added.
The Hague police said on Twitter that they had arrested three people in a museum for "public violence against goods".
Dozens of people were gathered inside the museum waiting for news, while security guards told them not to get too close to the other paintings, an AFP reporter said.
The entrance to the room where the "Girl with a Pearl Earring" normally hangs was blocked off by a large reproduction oil painting and a guard said it would likely be closed for the rest of the day.
Two police vans were parked outside the museum while investigations continued.