In the first confirmed airstrike by Kyiv on Russian land, Ukrainian helicopters targeted a gasoline storage station in western Russia, igniting a massive fire, according to the regional governor. The declaration occurred on the 37th day of Russia’s military campaign in Ukraine, which has resulted in thousands of deaths and over 10 million people displaced in Europe’s biggest refugee crisis since WWII. The bombing near Belgorod, Russia, was the first time the country has acknowledged a Ukrainian airstrike on its soil since the conflict began.

“There was a fire at the petrol depot because of an airstrike carried out by two Ukrainian army helicopters, which entered Russian territory at a low altitude,” Belgorod region governor Vyacheslav Gladkov stated at Telegram app.

In another tweet, he stated that two employees at the storage facility were hurt in the incident. At 170 firemen were tackling the massive wildfire, which began around 6 a.m. (0300 GMT), according to the emergency ministry. According to a video posted by the ministry, a big fire was blazing with black and white smoke pouring overhead. The facility’s owner, the Russian oil company Rosneft, claimed it had evacuated its employees.

Long lineups of automobiles formed at gas stations, but the governor advised citizens not to worry, claiming that there was adequate gasoline.

“There aren’t any problems with fuel in the region and there won’t be any,” Gladkov added.

Explosions were heard at an armaments store in Belgorod earlier this week, but the authorities could not give a clear explanation for the booms.

Belgorod is around 40 kilometers (25 miles) from Russia’s Ukrainian border and about 80 kilometers from Kharkiv, which has been pounded by Russian forces since Moscow dispatched soldiers to Ukraine on February 24. Meanwhile, Russia’s military source announced the destruction of six army bases in Ukraine, including five depots carrying rockets, ammunition, and artillery weaponry.