Wildfires in Bolivia destroyed 3,500-year-old rock art.

Wildfires in eastern Bolivia have destroyed sites of rare rock art, archaeologists said Tuesday. The fires have been raging for weeks, and The Guardian estimated nearly 2.5 million acres of farmland and forest had been lost as of last week. Particularly hard hit is the state of Santa Cruz, which is home to many rock art sites spanning millennia.

“We believe that the damage is big and wide in terms of our heritage of rock art,” Danilo Drakic, chief archaeologist in the region, told the AFP. He said a dark layer of soot has covered the paintings and heat from the fires has caused rocks to break apart. The full extent of damage from the wildfires cannot be assessed until they have been put out. The Bolivian Rock Art Research Society posted a plea on Facebook Saturday asking for more information about what will happen to the rock art.

Sites near the town of Roboré, where certain engravings date back to 1500 B.C.E., have been damaged by the fires, Drakic said. Authorities declared the town the “departmental capital of rock art” in 2017, according to the AFP. The fires are also endangering the Jesuit Missions of the Chiquitos, UNESCO World Heritage Sites that were built in the 17th and 18th centuries.

Critics of Bolivia’s president Evo Morales say that the fires are a result of a new law permitting slash and burn farming practices, which are used by farmers to clear land quickly, while Morales’ government says high winds and dry conditions caused the fires. In addition to the destruction of rock art, indigneous populations and hundreds of animal species, including 35 endangered species, are affected.