Peru is planning to criminally charge Greenpeace activists who are said to have damaged the world-renowned Nazca lines by leaving footprints in the desert nearby during a publicity stunt.

Peru’s culture ministry said that activists entered a “strictly prohibited” area beside the enormous figure of a hummingbird at the United Nations world heritage site in the country’s coastal desert, the Guardian reports. The Nazca figures, scratched on the surface of the ground between 1,500 and 2,000 years ago, depict creatures, plants and imaginary figures.

The Peruvian government says that it is trying to prevent the activists responsible from leaving the country while prosecutors file charges of attacking archaeological monuments.

“Peru has nothing against the message of Greenpeace. We are all concerned about climate change,” said Luis Jaime Castillo, the deputy culture minister. “But the means doesn’t justify the ends.”

A Greenpeace spokesman said that activists were “absolutely careful to protect the Nazca lines.”

[The Guardian]

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