A Russian official said on Friday that two Ukrainian military helicopters had hit a fuel depot in the Russian city of Belgorod, just 40 kilometers from the border with Ukraine. Later in the day, a new explosion was heard in the Russian city, a witness told Reuters. The video of the alleged attack posted on the Internet and reported by Reuters showed that it looked like several rockets were fired from a low altitude, followed by an explosion. Reuters, however, said it could not independently verify the allegations. The helicopters hit the facility after crossing the border at low altitude, Regional Governor Vyacheslav Gladkov told the Telegram messaging app. The resulting fire injured two workers, Mr. Gladkov added, while some areas were evacuated in the city. However, the Russian oil company Rosneft, which owns the fuel depot, said in a separate statement that no one was injured in the blaze, although it did not provide information on the cause. An ammunition depot near Belgorod caught fire on Wednesday, causing a series of explosions. Mr Gladkov said at the time that authorities were waiting for the Russian Defense Ministry to reveal his cause. This is the first time Ukraine has been accused of carrying out an attack on Russian soil since the deadly invasion of the country on February 24, which left more than 10 million people displaced and thousands dead. Russia, which calls its action in Ukraine “a special military operation,” has lost between 7,000 and 15,000 troops since the start of the war, according to the latest NATO estimates. The Independent has a proud campaign history for the rights of the most vulnerable and we first launched our “Welcome Refugees” campaign during the war in Syria in 2015. Now, as we renew our campaign and start this report on In the wake of the unfolding Ukrainian crisis, we call on the government to move faster and faster to secure aid. To learn more about our Refugee Campaign, click here. To sign the application click here. If you would like to donate, click here for our GoFundMe page. Additional reports from agencies