Ukraine has not confirmed that it launched the attack, raising questions about whether Russian negligence could be held responsible. A Russian commander in the Belgorod border region said early Friday that two Ukrainian Mi-24 helicopters crossed the border at low altitude before firing rockets at an oil facility 25 miles from the border. Ukrainian Foreign Minister Dmitry Kuleba said he could not confirm or deny reports of Ukrainian involvement in the attack, as he had no military information, Reuters reported. The Ukrainian Ministry of Defense has not responded for comment. Some prominent Ukrainian commentators have suggested that the attack could be a “false flag” intended to justify a Russian mobilization or negotiations. On Friday, Kremlin spokesman Dmitry Peshkov fueled the rumors, saying the attack could hamper negotiations, although he stopped announcing any specific response to the alleged attack. “What happened is certainly not something that can be seen as creating comfortable conditions for the negotiations to continue,” Peshkov said. Map The video, which was posted on social media on Friday, appears to show a helicopter attack with surface-to-air missiles and then a large fire at a facility said to be located in Belgorod, with the flames reaching tens of meters in the air. Reports indicated that the facility continued to burn until noon on Friday, with dozens of firefighters dispatched to deal with the inferno. Other videos showed helicopters, used by both Ukraine and Russia, flying over the area. “The fire at the oil depot was caused by an air strike by two helicopters of the Ukrainian armed forces, which entered the territory of Russia at low altitude,” said Governor Vyacheslav Gladkov. “There are no victims” There have been other incidents in Belgorod, which has served as an important hub for Russian military units involved in the invasion of Ukraine. There was an explosion earlier on Thursday at a weapons depot there, speculating that saboteurs were targeting the city. Russia’s Tass news agency reported that four employees of the agency were injured in the blast. The bomber struck shortly after noon in front of a Russian military base, announcing it was ending its offensive in Kyiv after its troops met heavy resistance in a month-long war. Western officials have warned that Russia could deploy troops in a major offensive in eastern Ukraine.