Something very strange is happening to dogs on the streets of New Mumbai in India. They're turning blue, and a very unnatural shade of blue at that, reports the Hindustan Times. The bizarre phenomenon is hard to miss; the vivid sky-blue shade almost makes them look like they are radioactive.

What in the world is going on? Officials suspected the unsettling coloration was caused by pollutants in the nearby Kasadi river, a waterway lined by industrial factories. In this case, the pollutant of concern is blue dye, which might not sound so bad, but it's a very visible symptom of a larger, often invisible underlying pollution problem.

“It was shocking to see how the dog’s white fur had turned completely blue,” said Arati Chauhan, resident of Navi Mumbai. “We have spotted almost five such dogs here and have asked the pollution control board to act against such industries.”

The board investigated these complaints, and on Wednesday shut down a manufacturing company after concluding that dogs were turning blue due to air and water pollution from the facility, according to the Guardian.

The region is home to nearly 1,000 pharmaceutical, food and engineering factories. A recent water quality test at Navi Mumbai Municipal Corporation found that the waste treatment was inadequate. Levels of biochemical oxygen demand (BOD) — the concentration of oxygen required to sustain aquatic life — was 80 milligram a liter (mg/L). To put that in perspective, fish die when BOD levels are above 6 mg/L, and levels above 3 mg/L make the water unfit for human consumption. Levels of chloride, which is toxic, were also high.

The polluted river is also an important resource for local communities. Fishermen are, however, vastly outnumbered by the 76,000 some workers that are employed by the factories that generate the pollution, and little has been done when complaints have been filed before.

There's nothing quite like bright, blue-hued dogs to signal the alarm bells, however. Hopefully this will be the wake-up call that is needed to finally crack down on polluters.

Editor's note: This article has been updated since it was originally published Aug. 18.