CAUGHT ON VIDEO: WTH?? Mystery Sulfur Toxic Fog Blankets City Of Moscow!

What the heck is going on in Russia? Toxic gas covering the city?? 

UPI Moscow -

Moscow residents awake Monday to a foul-smelling, sulfurous gas blanketing the city.

Officials have recommended people stay indoors until the cause of the smell, as yet undetermined, has been resolved. Media reports say the smell is of hydrogen sulfide, which smells like rotten eggs and can be highly toxic if breathed.

Russian Parliament members, in a building adjacent to the Kremlin, noted the odor. "Guys, who knows what the reason for such a stink in Moscow," a Twitter comment from legislator Sergei Krasinikov said.

The Russian news agency Interfax reported the country's Emergencies Ministry blamed the odor and fog on a Moscow oil refinery, but Gazprom Neft, the refinery operator, said no accident had occurred and hydrogen sulfide level there were normal. A prior report by the news agency Tass claimed a wastewater treatment facility was to blame.

Moscow meteorologists noted weather conditions were "not conducive to the rapid dissipation of pollutants in the air."

A YouTube video posted by Анна Кашуба showed the sun over Moscow nearly occluded by the fog.