A 36-year-old man has been arrested and placed in psychiatric care after he smeared a glass screen encasing the Mona Lisa with cake in a purported protest against artists not focusing enough on “the planet”.

Officials at the Louvre Museum in Paris, where the enigmatic portrait holds pride of place, declined to comment on the bizarre incident on Sunday, which was captured on several phones and circulated widely on social media.

The work by Leonardo da Vinci, which has been the target of vandalism attempts in the past, was unharmed thanks to its bulletproof glass case.

The piece, which was undamaged, was left with white cream smeared across its protective glass.

The perpetrator, seen wearing a wig and lipstick, urged people to "think of the Earth" while being led from the scene.

The incident on Sunday was described by witnesses as being "jaw-dropping".

Louvre visitor Luke Sundberg, from the US, saw it all unfold. "The crowd begin gasping and we looked up and some man in a wheelchair [dressed] as an old lady ran up to the painting and started punching it before smearing cake all over it," the 20-year-old told the PA news agency.

"It took about 10 to 15 seconds for the security to actually take the man away, but the crowd seemed to panic a little bit.