Russia’s Energy Ministry has acknowledged that mounting Ukrainian drone attacks on the country’s oil refineries and energy infrastructure are to blame for recent shortages of gasoline in annexed Crimea and some parts of southern Russia.

“Recently, fuel and energy sector enterprises have faced an uptick in enemy aerial attacks, leading to temporary difficulties with fuel supplies in several southern regions,” the Energy Ministry said in a statement released late Monday.

Officials said they have set up an “industry-wide task force” meant to ensure the “stable and efficient operation of the country’s entire energy sector.”

Ukraine began ramping up its attacks against Russian oil refineries and supply lines this spring in a bid to deprive the Kremlin of windfalls from surging oil prices. Drone strikes have halted or scaled back production at facilities that account for large shares of Russia’s gasoline output.

In addition to attacking Russian refineries, Ukraine is targeting fuel trucks driving along the R-280 Novorossiya highway, which connects annexed Crimea to southern Russia’s Rostov region.