An explosion occurred at an abandoned thermal power plant in Pavlovsk, a town near St. Petersburg, on Wednesday evening, the news site Fontanka reported. According to the outlet, the blast was heard “by the entire town,” and completely destroyed the facility, leaving a 6-by-1.5-meter (20-by-5-foot) crater in its place.
Bomb technicians who traveled to the site after the explosion were unable to immediately determine its cause. According to Fontanka, the blast could have resulted from a shell left over from the Second World War.
On Thursday, the Russian Investigative Committee’s St. Petersburg branch confirmed the explosion, reporting that it was caused by an “unidentified device.” The Russian authorities have opened a criminal case for the illegal acquisition and storing of explosive materials or devices.