Ukraine sent waves of drones to attack power plants, oil refineries and other sites across Russia, including in Moscow, before dawn on Sunday, Russian authorities and news media said, in what appeared to be part of a ferocious battle being waged by both sides against each other’s energy facilities.

The Russian military characterized the assault as one of the largest since it launched its full-scale invasion against Ukraine two and half years ago, and it claimed to have shot down all 158 drones launched by Ukrainian forces across 15 regions.

However, Russian state media and local officials reported fires and explosions caused by drone attacks at a number of facilities, including an oil refinery in Moscow and one of the largest energy production facilities in the central Russian region of Tver.

Many of the drones were directed at targets in the regions of Kursk, Bryansk, Voronezh and Belgorod, all of which border Ukraine, according to the Russian military. The reports by Russian officials could not be independently verified.

Ukrainian officials did not immediately comment on the attacks. But the Ukrainian military has repeatedly targeted Russian oil and gas facilities in what it has said is an effort to undermine Russia’s ability to supply its forces with fuel and cut into the energy revenues that fund the Kremlin’s war effort.

It is difficult to assess the effect of the overnight attacks or the overall Ukrainian campaign. As the number of Ukrainian strikes has increased, Moscow has increasingly limited the information it releases on its oil industry.