The Emergency Situations Ministry has said Moscow's sewers were to blame for a mysterious "chemical" smell that prompted complaints in a number of the city's districts.
In a statement on its website, the ministry said Monday that the fumes had been caused by the presence of ethyl acetate in Moscow's sewers, adding the substance did not pose a health threat.
On Sunday, the ministry issued a warning advising Muscovites to close their windows if they noticed a "chemical" smell, following complaints from residents in the capital's Sokolniki, Lefortovo and Nagatinsky Zagon districts about a mysterious stench in their neighborhoods.
A warning issued online recommended that residents stay indoors, keep their windows and doors shut, and seal any door cracks with wet towels.
An official for the Moscow branch of the emergency agency, Andrei Pavlov, told radio station Govorit Moskva that test results showed the concentration of air pollutants in the capital had not exceeded permissible limits on Sunday or Monday.
Pavlov added that the sewers "were mostly to blame for the odors," without specifying what else might have caused the smell.
Ethyl acetate, a colorless liquid with an intense smell, is used in various industries. Its fumes can provoke irritation of the eyes and the respiratory tract.