The Ukrainian military said Wednesday that it struck a fuel storage depot deep inside Russia, causing a huge blaze at the facility that supplies an important Russian air base.

Russian officials acknowledged a major drone attack in the area, and said that authorities had set up an emergency command center to fight the fire.

Ukraine’s General Staff said that the assault hit the storage facility near Engels, in Russia’s Saratov region, about 600 kilometers (370 miles) east of the Ukrainian border. The depot supplied a nearby airfield used by aircraft that launch missiles across the border into Ukraine, a statement on Facebook said.

Ukraine has been developing its arsenal of domestically produced long-range missiles and drones capable of reaching deep behind the front line as it faces restrictions on the range that its military can fire its Western-supplied missiles into Russia.

The attacks have disrupted Russian logistics in the almost three-year war, which began on Feb. 24, 2022, and embarrassed the Kremlin.

Ukrainian President Volodymyr Zelenskyy said last year that his country has developed a weapon that could hit a target 700 kilometers (400 miles) away. Some Ukrainian drone attacks have hit targets more than 1,000 kilometers (600 miles) away.

The governor of the Saratov region, Roman Busargin, said that an unspecified industrial plant in Engels sustained damage from the falling drone debris that sparked a fire, but nobody was hurt.

Engels, which has a population of more than 220,000, is located on the left bank of the Volga River, and is home to multiple industrial plants. Saratov, a major industrial city of about 900,000, faces Engels across the river.

“The damage to the oil base creates serious logistical problems for the strategic aviation of the Russian occupiers and significantly reduces their ability to strike peaceful Ukrainian cities and civilian objects. To be continued,” the statement from Ukraine’s General Staff said.

Russian authorities restricted flights early Wednesday at the airports of Saratov, Ulyanovsk, Kazan and Nizhnekamsk, in an apparent response to the Ukrainian attack.

The main base of Russia’s nuclear-capable strategic bombers is located just outside Engels. It has come under Ukrainian drone attacks since the early stages of the war, forcing the Russian military to relocate most of the bombers to other areas.

(AP)