Ukraine has reportedly launched at least 121 drone strikes targeting Moscow, striking a Russian oil refinery, in one of the most significant single operations conducted during the war. 

Video footage confirmed by the BBC shows a massive fireball rising from an oil refinery and pumping station in the Ryazan region, southeast of Moscow. Ukrainian officials identified this refinery as the target of a recent attack.

Russia reported that it successfully shot down 121 drones aimed at 13 regions, including Ryazan and Moscow, but claimed that no significant damage was caused.

In a separate incident, Ukrainian authorities reported that three people were killed and one was injured when a Russian drone struck a residential building in the Kyiv region.

Andriy Kovalenko, head of Ukraine's counter-disinformation centre, shared on Telegram that both the oil refinery in Ryazan and the Kremniy factory in Bryansk, which produces missile components and other weapons, had been targeted by Ukrainian strikes.

Images and videos posted by bloggers on Telegram show raging fires at the Ryazan facility, which spans approximately 6 square kilometres (2.3 square miles). Verified footage shows people fleeing the site in cars and on foot as flames rise into the sky.

The BBC Verify team used video evidence to confirm the locations of the two fires at the refinery. One video showed a fire near the northern entrance, verified using road signs, fences, and the surrounding layout. Two other videos revealed a more effective fire on the eastern side of the refinery, about 3 kilometres (1.6 miles) from the first fire, with the location confirmed by matching the trees, pylons, and road structures seen in the footage.

According to the Russian state-owned news agency RIA, the Kremniy factory in Bryansk has suspended operations after being targeted by six drones. Regional Governor Pavel Malkov reported that emergency services are responding to the incident.

The Kremlin acknowledged the drone attacks but did not provide any details on the extent of the damage or casualties. It reported the destruction of 121 Ukrainian drones, including six in the Moscow region, 20 in Ryazan, and several over the Bryansk border area.

Moscow's mayor, Sergei Sobyanin, stated that the city’s air defences had intercepted Ukrainian drones at four locations. He added that air defences south of Moscow, in Kolomna and Ramenskoye, had also successfully repelled drone attacks, though the exact number was not disclosed. Sobyanin emphasised that there were no reported damages.

According to Russian news agencies, Rosaviatsiya, the federal aviation authority, confirmed that Moscow's Vnukovo and Domodedovo airports had resumed flights after temporarily suspending operations. Six flights were diverted to alternative airports.

In Kursk, Mayor Igor Kutsak reported that overnight drone attacks had caused damage to power lines, resulting in an electricity outage in one district.

Meanwhile, in Ukraine, officials reported that air defences had shot down 25 of the 58 drones launched by Russia overnight. The country’s interior ministry also stated that debris from one of the drones killed two men and a woman in Hlevakha, Kyiv region, and injured another person.

Russia's Justice Ministry has labelled Olga Ivshina, a BBC Russian service journalist based in London, as a "foreign agent". This designation makes her the fourth BBC journalist to receive this label since Russia's full-scale invasion of Ukraine in February 2022. Last week, two more BBC Russian journalists, Anastasia Lotareva and Andrey Kozenko, were added to the list.

Being designated as a "foreign agent" comes with significant restrictions. Those labelled must mark any online content accessible in Russia as being produced by a "foreign agent" and disclose their financial information. Failure to comply with these requirements can result in fines or even imprisonment.

A BBC spokesperson stated that the organisation "strongly rejects and will challenge the designation."

They emphasised, "The role of BBC News Russian journalists, reporting independently and impartially, has never been needed more, and we will support them to ensure they can continue to do their jobs serving Russian-speaking audiences."