A loud explosion in the city of Tula, Russia, on Sept. 21 was followed by a major power outage in one district, the Russian independent media outlet Meduza reported on Telegram.
Residents reported hearing sounds of an explosion before the lights went out in the city's Zarechensky district.
The Russian state news outlet RIA Novosti claimed that 5,000 residents in the Zarechensky district lost power.
Russia's Emergency Situations Ministry claimed the blackout was caused by technical failure, and was not connected to sounds of an explosion.
"Work to restore power supply to the Zarechensky district of the city of Tula will be completed in the near future," the ministry said.
The ministry's statement also speculated that the noises residents attributed to an explosion were caused instead by an aircraft transitioning "to supersonic speed."