The Ukrainian military said on Wednesday (Jan 8) that its forces hit a Russian oil depot which was used by Moscow's air force.
In a statement on social media, the Ukrainian general staff said that the military hit the oil depot in Engels in the Saratov region.
"This oil depot provided fuel to the Engels-2 military airfield, where enemy strategic aviation is based," the statement added.
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A report by the news agency AFP said that the attack was the latest in a series of escalating cross border strikes by Moscow and Kyiv targeting energy and military facilities.
Russia acknowledges attack in Saratov
Earlier, Russian officials acknowledged in statements that Ukraine attacked in the Saratov region with unmanned aerial vehicles (UAVs).
The Russian defence ministry said that its air defence systems had downed 32 Ukrainian drones overnight, including 11 over Saratov.
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The region's Roman Busargin said that an emergency response team had been dispatched to an industrial facility where a fire had broken out after a Ukrainian drone attack, without elaborating on the type of facility hit. No injuries were reported.
Russia attacks Ukraine with 64 drones
This attack on the oil depot comes a day after the Ukrainian military said that Russia launched 64 drones at the country overnight.
Of those drones, Ukraine's air force shot down 41, while 22 "imitator drones" did not reach their targets, the air force added.
(With inputs from agencies)