The video, which was shared on social media, shows the drone crashing into the Novoshakhtinsk oil refinery in Rostov, in what would have been a shameful infiltration of Russia’s air defense systems into the ongoing war in Ukraine. Ukraine used drones during the war, but did not claim responsibility for the alleged attack. Subscribe to the First Edition, our free daily newsletter – every morning at 7 p.m. BST Russia’s Rostov-on-Don governor, Vassily Golubev, appeared to confirm the incident, saying the wreckage of two drones was found on the ground at the Novosakhtinsk oil refinery, where a large fire broke out on Wednesday morning. A video posted on Russian social media shows a drone approaching the oil refinery as workers watched. “Do you think it is Ukrainian?” asked one. “Of course not,” replied another. “Where did he go;” he added, as the drone disappeared from his sight. Moments later, a huge explosion rocked the refinery. “Bugger!” shouted the spectators. As the fire started raging at the refinery, the unknown cameraman said in a resigned manner: “This is happening, children.” Footage broadcast by Russian state television shows firefighters battling the blaze at the oil refinery, which shut down production on Wednesday. Authorities said the fire was contained. Some bridges and other key infrastructure in Russia’s border regions have been damaged since the Kremlin launched a new offensive against Ukraine in February. In most cases, Russia has not admitted to being the victim of sabotage or cross-border attacks that have penetrated its defenses. If the refinery attack is confirmed, it would indicate that the drone was either launched from inside Russia or that it had passed through Russian-controlled territory to reach the refinery, passing through Russian air defense systems along the way. No one was injured in the incident at the oil refinery, the Rostov governor said. In another incident Wednesday, however, four people were killed in an explosion at an ammunition depot in Russia’s Vladimir region after an object “exploded spontaneously during a loading and unloading operation,” a Russian military press service said. Three of the victims were soldiers, while another was a specialist.