A major Ukrainian drone offensive struck Moscow and surrounding areas as Russia entered the final day of its parliamentary elections, leaving at least two people dead and causing damage to an important oil refinery and residential buildings, according to Russian authorities.

Moscow Mayor Sergei Sobyanin described the attack as unprecedented. He said Russian air defenses had intercepted more than 1,600 drones since Saturday, including around 450 heading toward Moscow. Several drones reportedly reached the grounds of the Moscow Oil Refinery, while another struck a residential building.

The attack also caused casualties in the Moscow region. Russian officials initially reported that at least two people had been killed, while later reports gave differing casualty figures as authorities continued assessing the damage.

Ukraine's President Volodymyr Zelenskyy confirmed that Ukrainian forces had targeted a Russian oil-industry facility and a logistics site. He described the targets as important to Russia's ability to finance and sustain its military operations.

The timing of the attack has drawn particular attention because it occurred on the final day of Russia's three-day parliamentary election. Russian officials accused Ukraine of attempting to disrupt the vote. That is an allegation from Russian authorities; independent reporting has established the timing of the attack but does not independently establish its stated purpose.

The election itself is the first Russian parliamentary election since the country's full-scale invasion of Ukraine began in 2022. International reporting has highlighted the tightly controlled political environment surrounding the vote, including restrictions on opposition participation.

The strikes demonstrate how the Russia-Ukraine conflict continues to extend beyond the front lines. Energy infrastructure has increasingly become a target of long-range attacks, with oil refineries and other facilities playing an important role in Russia's economy and fuel supply.

The Moscow refinery is particularly significant because it supplies fuel to the capital and surrounding areas. Damage to the facility comes amid wider reports of pressure on Russia's fuel market following repeated attacks on energy infrastructure.

For residents of Moscow, the latest attack brought the war directly into the capital once again. Local authorities reported evacuations after a drone damaged a high-rise residential building, while emergency crews responded to fires and other damage.

The wider drone campaign also affected other parts of Russia. Russia's Defence Ministry reported that more than 1,100 drones had been intercepted across Russia, occupied Ukrainian territories and the Black Sea during the overnight attack.

Ukraine has increasingly used long-range drones to strike targets deep inside Russian territory, particularly energy and military-related infrastructure. Russia, meanwhile, continues to launch large-scale drone and missile attacks against Ukraine.

The latest escalation comes at a politically sensitive moment for Moscow and highlights the continuing connection between the war, Russia's energy infrastructure and domestic security.

PK-News.com will continue monitoring developments from Moscow, Kyiv and other affected regions. Follow PK-News.com for further updates, verified developments, casualty figures and official statements as more information becomes available.