MOSCOW, November 12 (RAPSI) – The police has opened a crimininal case following a massive hydrogen sulfide emission in Moscow, according to the Prosecutor’s Office statement released on Wednesday.

On Monday, November 10, Central, South and South East districts of Moscow were covered in a dense cloud erupting a strong smell of hydrogen sulfide. Citizens of South East district of Kozhukhovo reported earliest instances of emissions as early as 9:00 in the Morning. By noon, the cloud dispersed as far as central Moscow, including the Red Square.

Initial reports made by atmosphere control stations indicated that hydrogen sulfide levels exceeded safe levels 4,6 times, and styrene levels 2,4 times.

EMERCOM advised citizens to stay at home and keep windows closed, but later denied any health risks from exposure.

Later on Monday, EMERCOM Moscow deputy head Yuri Akimov stated that the cause of “unpleasant” smell was an incident at the Moscow Oil Refinery. Same day Gazprom Neft - the facility’s operator, stated that the information was false.

Prosecutor’s Office conducted a probe at the facility, and opened a criminal case on the grounds of villation of noxious substances emission of Russian Criminal Code.