A source in Ukraine’s SBU state security service said its drones had caused an “extremely powerful detonation”. It is not clear exactly which weapons were being stored at the warehouses at the time of the explosion, but Ukraine said they included missiles intended for tactical launch systems and guided bombs.

Russian sources have previously described the storage location of an area of significant importance for Moscow’s armed forces. The site covers an area around two square miles in size, while its outside perimeter is roughly seven miles.

In 2018, Dmitry Bulgakov, a Russian general, said: “The arsenal in Toropets allows us to shelter reserves of missiles and ammunition from external influences and ensure their safety and fire and explosion safety.”

The military site has been targeted by Ukraine twice before, in May and June, according to Astra, the Russian Telegram news channel.

Russian officials attempted to downplay the scale of the strike, claiming air defence crews had repelled a Ukrainian drone attack.

The country’s defence ministry reported that its forces had destroyed 54 Ukrainian drones overnight without mentioning the attack on the storage site.

Local authorities were carrying out evacuations of the civilian population living near the base in Toropets. Schools and nurseries were also cancelled on Wednesday in parts of Russia’s Tver region.

On Wednesday morning, Igor Rudenya, the region’s governor, delivered a speech to camera while explosions were still ringing out in the distance.

Russia’s emergency text message broadcast system pinged mobile phones near the military base, asking people not to publish images of explosions and drones on social media.

Andriy Yermak, chief of staff to Volodymyr Zelensky, the Ukrainian president, acknowledged the attack by sharing a video of the explosion, commenting: “The demilitarisation of Russia is necessary to end terror.”