Russia has reported what its Defence Ministry described as the largest Ukrainian drone attack since the start of the full-scale war, with the assault taking place as Russians cast ballots on the final day of the country's parliamentary elections.

Russian authorities said thousands of drones and missiles were involved in attacks across Russian-controlled territory during September 19 and 20, while Moscow and the surrounding region came under a particularly large overnight drone assault.

The reported attacks caused deaths, injuries and damage to infrastructure, including an oil refinery in the Russian capital.

Russia Reports 1,951 Drones and Eight Missiles

Russia's Defence Ministry said its air-defence forces intercepted 1,951 Ukrainian fixed-wing attack drones and eight long-range Flamingo cruise missiles during the 24-hour period.

The ministry said the attacks were launched between September 19 and 20 and claimed they were intended to disrupt Russia's State Duma elections.

Russian officials said another cruise missile deviated from its course and fell in an uninhabited area.

The figures are claims from the Russian Defence Ministry and have not been independently verified.

450 Drones Reportedly Targeted Moscow

Moscow Mayor Sergei Sobyanin said more than 1,600 drones had been intercepted since Saturday, including around 450 that were heading towards Moscow.

He described it as the largest drone attack against the capital since Russia launched its full-scale invasion of Ukraine in February 2022.

Russian authorities said air defences prevented the majority of the drones from reaching their intended targets.

However, some drones caused damage inside the Moscow metropolitan area.

Oil Refinery Hit

The Moscow oil refinery in the Kapotnya district was damaged during the attack.

Ukraine's Security Service said on September 20 that its forces, together with other Ukrainian defence units, had struck the refinery using long-range drones.

The Ukrainian statement said the facility was hit and a large fire was reported.

The refinery is one of Russia's major fuel-processing facilities and has previously been targeted during the war.

Deaths and Injuries in the Moscow Region

Russian authorities reported deaths and injuries in the Moscow region following the drone attacks.

Andrei Vorobyov, governor of the Moscow region, said 249 Ukrainian drones had been brought down across 17 districts.

He reported two deaths in the region, in the Orekhovo-Zuyevsky and Ramensky districts, and 20 people injured.

Reuters separately reported three deaths in the broader Moscow-region attack, reflecting a subsequent update to the casualty toll.

Residential Buildings Damaged

Residential property was also affected.

Russian officials reported damage to apartment buildings in the Moscow region, with emergency services carrying out evacuations in affected areas.

In Ramensky district, around 400 residents were evacuated after a residential building was damaged, according to reports citing regional authorities.

The damage occurred alongside strikes against industrial and other infrastructure.

Flights Disrupted

The attack also disrupted civil aviation around Moscow.

The city's three main airports faced restrictions during the overnight drone assault, with flights delayed, cancelled or diverted while airspace restrictions were imposed.

The disruption affected passengers travelling through Moscow during the final day of voting.

Russia Links the Attack to the Election

Russian officials explicitly linked the attack to the parliamentary election.

Sobyanin said the assault had been planned with the aim of disrupting voting, while the Defence Ministry similarly said Ukraine had attempted to interfere with the electoral process.

Those statements describe the Russian authorities' assessment of the attack's purpose. No independent evidence establishing the alleged motive was publicly available.

Ukraine did not publicly confirm that the overall drone operation was intended to disrupt the election.

Final Day of the State Duma Election

The attacks took place on Sunday, September 20, the third and final day of Russia's State Duma election.

Voting had begun on Friday, September 18.

The election filled all 450 seats in the lower house, with 225 seats allocated through party lists and 225 through single-member constituencies.

The election was the first parliamentary vote in Russia since the full-scale invasion of Ukraine began in February 2022.

Voting in Russian-Controlled Ukrainian Territories

Russia also held voting in areas of Ukraine under its military control.

Ukraine has rejected the holding of Russian elections in those territories and considers the process illegitimate.

The inclusion of those areas has been another point of international dispute surrounding the election.

United Russia Wins Parliamentary Majority

The election concluded with the Kremlin-aligned United Russia securing 355 of the 450 seats in the State Duma, according to the Russian Central Election Commission.

Reuters reported that United Russia received 57.83% of the vote, giving the party a constitutional majority in the chamber.

The result followed an election campaign in which most major anti-war opposition candidates were excluded from competing nationally.

Ukraine Confirms Strike on Moscow Refinery

While Kyiv has not independently confirmed Russia's overall figures of 1,951 drones and eight missiles, Ukraine's Security Service publicly claimed responsibility for the strike on the Moscow refinery.

The Ukrainian agency said the operation involved its forces together with other branches of Ukraine's defence forces.

It described the refinery as a major element of Russia's oil-refining industry and said the strike was aimed at reducing Russia's fuel and energy capabilities.

A Wider Pattern of Long-Range Drone Attacks

The latest assault is part of an expanding campaign of Ukrainian long-range attacks against targets inside Russia.

Ukrainian officials have increasingly acknowledged strikes against oil refineries, logistics sites and other infrastructure that Kyiv says supports Russia's war effort.

Russia has also continued to launch large-scale drone and missile attacks against targets across Ukraine.

Both countries say they are targeting military or strategic infrastructure and both deny deliberately targeting civilians.

Damage to Energy Infrastructure

The Moscow refinery is strategically significant because of its role in supplying fuel to the capital and surrounding region.

Reuters reported that crude processing at the facility was subsequently suspended after fires damaged major refining units. Repairs were expected to take several weeks, according to industry sources cited by the news agency.

The development comes amid wider disruption to Russia's refining sector and domestic fuel markets.

No Independent Verification of the Full Attack Figure

The headline figure of 1,951 drones comes from Russia's Defence Ministry.

Independent reporting confirms the scale of the overnight assault and the hundreds of drones reported around Moscow, but the total number of Ukrainian drones launched cannot currently be independently established.

For that reason, the figure should be presented as a Russian government estimate rather than an independently verified count.

The Final Day of Voting Continues Despite the Attack

Despite the attacks and disruption in Moscow, Russian authorities said the parliamentary voting process continued.

The drone offensive did not prevent the completion of the three-day election.

Russian officials described the electoral process as having continued despite the security incidents, while Ukrainian authorities had previously criticised the election and the inclusion of occupied Ukrainian territories.

A Major Escalation Around Moscow

The September 19-20 attack represents a significant episode in the continuing long-range conflict between Russia and Ukraine.

The reported scale, the damage to the Moscow refinery and the deaths and injuries in the Moscow region occurred at the same time as Russia's parliamentary vote was reaching its final day.

While the Russian government says the attack was intended to disrupt the election, that attribution of motive remains a claim by Moscow.

What is independently established is that a very large drone assault took place, Moscow's oil refinery was damaged, casualties were reported and air traffic was disrupted during the final day of voting.

What Happens Next

The immediate consequences are likely to include repairs to damaged infrastructure and continued security measures around Moscow and other Russian regions.

The Moscow refinery has already suspended crude processing following the damage, according to Reuters' reporting based on industry sources.

The attack also comes as both sides continue long-range strikes against energy and industrial infrastructure despite recent diplomatic efforts aimed at reducing attacks on such targets.

For now, the reported September 19-20 assault stands as one of the largest Ukrainian drone operations against Russia since the full-scale war began in 2022.