Last week, 57 children were treated in the town of Volokolamsk some 100 kilometers west of Moscow after they complained of nausea and dizziness linked to a nearby landfill.

Residents of Moscow and the Moscow region have been warned not to go outside, days after dozens of children living near a toxic landfill were hospitalized.

Local authorities have denied the connection between the pungent gases released by the dump and the medical complaints, insisting the abnormal levels of nitric oxide and hydrogen sulfide are not harmful.

Russia’s Emergency Situations Ministry said in an online statement on Wednesday afternoon that weather conditions between 6 p.m. on Wednesday and 10 a.m. on Thursday were expected to be “unfavorable for the dissipation of harmful pollutants in the atmosphere.”

Muscovites and people in towns in the Moscow region were advised to reduce the time spent outside, close their windows and switch on their air conditioners and air filters.



In a tweet several hours after the statement, the ministry said the warning had been mistakenly published as "urgent news." It added that the calm weather was no cause for an emergency warning and that it did not constitute a health hazard.