Nearly four decades after the Chernobyl nuclear disaster, the abandoned region continues to baffle the world — this time with a strange and eerie phenomenon. Several dogs living near the Chernobyl nuclear power plant have mysteriously turned blue, leaving caretakers and researchers completely stunned.

According to a report by the New York Post, these blue-coated dogs are descendants of pets left behind during the 1986 nuclear catastrophe that wiped out an entire city. The startling discovery was made by Dogs of Chernobyl, an organization associated with the non-profit Clean Futures Fund, which has been rescuing and caring for stray animals in the exclusion zone. In an Instagram post, the group revealed, “While capturing dogs for sterilization, we found three that were completely blue. We have no idea what’s causing it.”

Locals claim the dogs’ fur appeared normal just a week ago before suddenly changing color. A spokesperson for the organization said, “We suspect they might have come into contact with or ingested some kind of chemical. We’re investigating to find out more.” Interestingly, despite their unusual appearance, the dogs seem “active and healthy.”

Founded in 2017, the Dogs of Chernobyl program provides food and medical care to around 700 dogs living within the 18-square-mile exclusion zone. These animals are believed to be direct descendants of the pets left behind when residents were forced to flee after the catastrophic reactor explosion.

Even after 39 years, Chernobyl remains a haunting reminder of the world’s worst nuclear disaster. And now, with this bizarre incident of dogs mysteriously turning blue, it continues to raise unsettling questions about the lasting environmental effects of radiation in the region.