When a thick layer of mysterious, orange smoke blanketed the city of Chelyabinsk last week, terrified residents shuttered themselves indoors. Schoolchildren even missed their first day of class. Local authorities, however, did their very best to downplay the disaster.

The smoke came from a cargo train car at the Chelyabinsk railroad station. Officials said that it was caused by leaks in 20 one-litre bottles of bromine, a highly toxic chemical commonly used in insecticide, fumigants and flame retardants. This led to about 50 people being hospitalised for poisoning and chemical burns, according to officials. The real scale of the disaster, however, appears to be much worse. Data from a federal investigation, leaked to the press by doctors on Wednesday, shows that in reality, 6,000 bromine bottles were involved, and that several hundred people suffered serious health problems.

Toxic smoke spreading over homes in Chelyabinsk on September 1.

The local government is understandably unhappy about this, and has decided to improve the region’s image. At the end of July, renowned anti-corruption activist Alexey Navalny discovered that the Chelyabinsk regional government had put out a call for bids to help clean up its online reputation. It hoped to find a specialized company to find a way to make top search engines show results for positive or at least neutral articles about the region when people searched for phrases like “radiation in Chelyabinsk,” Mayak accident” or “Chelyabinsk region ecology.”