The cause of the explosions was not immediately clear. A witness said the blasts were so powerful that they shattered the windows of her Belgorod home. The blasts come days after the Russian Defense Ministry said two Ukrainian helicopters struck a fuel depot in the city, about 35 kilometers (22 miles) from the border with Ukraine, after entering Russia at an extremely low altitude in the early hours of Friday morning.[Readmore[readmore[Διαβάστεπερισσότερα[readmore Sign up now for FREE unlimited access to Reuters.com Register The Kremlin said the incident could undermine peace efforts, while a senior Ukrainian security official denied responsibility. A local official in the area around Belgorod said there was an explosion in the village of Tomarovka on Sunday, but that no one was injured and no one was injured. “There was a bang, debris fell to the ground,” Oleg Medvedev, head of the Yakovlevsky district outside Belgorod, wrote in the Messenger Telegram application. He did not elaborate on the nature of the wreckage or the cause of the explosion. It was not clear if the blast described by Medvedev was one of the blasts witnesses heard. Sign up now for FREE unlimited access to Reuters.com Register Report by Reuters. curated by Guy Faulconbridge Our role models: The Thomson Reuters Trust Principles.