A drone attack has destroyed a Russian weapons arsenal storing missiles, bombs and ammunition, according to a Ukrainian security source.
Unverified images and video on social media showed a large ball of flame shooting into the night sky and detonations across a lake.
NASA satellites detected heat from a site in the Tver region and monitoring stations recorded what sensors thought was a minor earthquake.
Regional governor Igor Rudenya said on Telegram that firefighters were trying to contain a blaze in the town of Toropets, but did not specify what was on fire.
Power outages were also reported by officials in Tver’s Zapadnodvinsky district.
A source in Ukraine‘s SBU security service told Reuters a weapons and ammo warehouse had been destroyed.
The drones caused an “extremely powerful detonation” at a large warehouse of the Main Missile and Artillery Directorate of the Russian Ministry of Defence in the town of Toropets, the source said.
“The warehouse contained missiles intended for Iskander tactical missile systems, Tochka-U tactical missile systems,
guided aerial bombs and artillery ammunition.”
After the attack, a fire covered an area 6km (3.7 miles) wide, the source added.
No information on casualties has been given and Moscow hasn’t yet commented.
Russia‘s state-owned RIA news agency said in 2018 that an arsenal for missiles, ammo and explosives was being built in Toropets.
The main explosion caught on video equates to about 200-240 tons of high explosives detonating, said George William Herbert from the US Middlebury Institute of International Studies.
The Tver region is northwest of Moscow and close to the border with Belarus.
Russian state news agencies, citing the defence ministry, said 54 Ukrainian drones launched against five western regions had been shot down overnight. However, the Tver region wasn’t mentioned.
Ukrainian attacks on Russia have increased as it’s ramped up domestic drone production, with officials saying they target infrastructure vital to Moscow’s war effort.
The country is also desperate to get approval to use Western-supplied long-range missiles, but so far permission hasn’t been given.
It says such a move would allow it to hit back at sites used to launch attacks on Ukraine as the two-and-a-half-year war drags on.
Meanwhile, Kyiv’s forces remain in the eastern Russian region of Kursk following a cross-border incursion last month.
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There were also Russian attacks on energy facilities in Ukraine’s northeastern city of Sumy on Wednesday, regional authorities said. One person was also killed in the central city of Kropyvnytskyi.
Ukraine’s air force said it shot down 46 of 52 drones launched overnight.
Repeated attacks on energy are said to be an attempt to damage Ukraine’s infrastructure before winter begins.