Strike comes a day after fierce Russian assault on Ukrainian capital Kyiv killed at least six people and injured dozens.

The Ukrainian army says it has struck a Russian oil refinery near the capital Moscow, a day after Russia launched massive, deadly attacks on Kyiv.

The Ukrainian army said on social media on Saturday that it hit a refinery in the Ryazan region as “part of efforts to reduce the enemy’s ability to launch missile and bomb strikes”.

The Russian attacks on Ukraine’s capital on Friday killed at least six people and wounded nearly three dozen more, with residential buildings and other sites targeted.

Describing it as a “wicked attack”, Ukrainian President Volodymyr Zelenskyy said about 430 drones and 18 missiles, including ballistic and aeroballistic missiles, were used in the Russian assault.

The Ukrainian strike on the Ryazan refinery comes as the two countries have been trading attacks on energy infrastructure, particularly ahead of another punishing winter of war, as they seek to gain an advantage in the nearly four-year conflict.

Last week, Ukrenergo, Ukraine’s state-run electricity transmission systems operator, announced that most regions across the country would undergo power cuts as crews worked to repair infrastructure damaged in Russian strikes.

Drone attacks, front-line battles

Separately on Saturday, Ryazan Governor Pavel Malkov said Russian air defences shot down 25 Ukrainian drones over the region during the night.

“Falling debris caused a fire on the premises of one enterprise,” Malkov said on Telegram, adding that there had been no casualties.

Russia’s RIA news agency also reported that the situation at the Russian-held Zaporizhzhia nuclear power plant in Ukraine remained stable after one external power line had been switched off.

The Dneprovskaya power line supplying electricity to the plant was switched off as a result of the automatic protection being triggered, the plant said a day earlier.

Meanwhile, the Ukrainian army faced difficult battles this week in the southern Zaporizhia region.

Ukrainian forces were forced to withdraw from five villages after intense fighting against Russian troops in the area.

Zelenskyy said in a video posted on social media on Thursday that he had spent the day in Zaporizhia at the front line and met with troops and other army leaders.

“The Russians want to do everything to make life unbearable for Ukraine,” he said. “We are doing everything to ensure protection for our state and all Ukrainians.”