Ukrainian drone attack triggers massive explosions in Russia's Tver region

(Reuters) – A major Ukrainian drone strike on Russia triggered a massive explosion on Wednesday and forced a partial evacuation of residents near a major Russian weapons arsenal in the Tver region, war bloggers and some media reported.

Unconfirmed videos and images on social media showed a huge fireball shooting high into the night sky and detonations thundering over a lake in the region northwest of Moscow and not far from the border with Belarus.

NASA satellites detected several springs emanating from the site early Wednesday, and earthquake monitoring stations recorded sensors indicating a minor earthquake in the area.

Firefighters were trying to contain the fire, Igor Rudenya, the governor of the Tver region, said in a post on the regional administration's Telegram news channel. He did not say what was burning.

According to a 2018 report by the state news agency RIA, Russia built an arsenal to store missiles, ammunition and explosives in Toropets, a 1,000-year-old town with a population of just over 11,000.

Russian state media had suspected that this was a large arsenal of conventional weapons.

There was no information about victims.

The force of the main explosion seen in the unverified social media video is equivalent to the detonation of 200 to 240 tons of high explosives, according to George William Herbert of the Middlebury Institute of International Studies in Monterey, California.

Reuters could not immediately confirm that a large weapons depot had been hit, according to state media reports. The Defense Ministry did not respond to a request for comment.

In Zapadnodvinsky district, which borders Toropetsky district, schools and kindergartens have been switched to online classes, the district administration announced on the social network VKontakte.

Russia's air defense units destroyed 54 drones that Ukraine fired at five western Russian regions overnight, Russian state news agencies cited a Russian Defense Ministry report as saying.

The regional governors reported that no damage was caused by the attacks.

However, the Defense Ministry's report did not mention the Tver region, which borders the Moscow region to the southeast.

Reuters could not independently verify the reports. There was no immediate comment from Ukraine.

Kiev had previously stated that its attacks on Russia targeted military, energy and transport infrastructure crucial to Moscow's war effort.

Russian officials rarely disclose the full extent of the damage caused by the Ukrainian attacks.

As Ukraine has ramped up its domestic drone production over the past two years, there have also been increased attacks on Russian territory.

In September, Ukraine's largest drone attack occurred in the Russian capital. At least one person was killed, houses were destroyed and air traffic at Moscow's airports was disrupted.

(Reporting by Lidia Kelly in Melbourne; additional reporting by Gerry Doyle in Singapore; Writing by Guy Faulconbridge; Editing by Michael Perry and Christian Schmollinger, William Maclean)