Reports from the Ukrainian and Russian sides differed as to the cause and scale of the attack.
ADVERTISEMENTA partial evacuation order is in place in Russia's Tver region after Ukrainian drones struck a large military depot in the town of Toropets.
According to a Kyiv security official, the attack was carried out by Ukraine's Security Service, along with its Intelligence and Special Operations Forces.
The Tver region is situated about 380 kilometres northwest of Moscow and roughly 500 kilometres from the border with Ukraine.
According to the official, the depot housed Iskander and Tochka-U missiles, as well as glide bombs and artillery shells.
He said the facility caught fire in the strike and was burning across a 6 kilometre-wide area.
The governor of the Tver region Igor Rudenya, meanwhile, said that a fire broke in Toropets after a Ukrainian drone was shot down by Russian air defence system.
"Today, as a result of the attack of unmanned aerial vehicles on the territory of the Russian Federation, the air defence system of the Ministry of Defence worked. The unmanned aerial vehicles were shot down, and a fire occurred when they fell," Rudenya claimed.
There was no immediate information about whether the incident caused any casualties.
Russian strikes continue
Meanwhile, Russian forces dropped three guided aerial bombs on a town in Ukraine’s Sumy region, injuring two people and damaging houses, vehicles and a grain elevator.
Russia's Ministry of Defence has also released footage of what is says shows Russian Sukhoi Su-34 fighter-bombers striking personnel and military equipment of the Armed Forces of Ukraine in the Kursk region.
It comes as residents in the Komyshuvakha community of the Zaporizhzhia region continue to deal with the damage caused by a massive Russian army attack in which two people were killed and five were injured.
The shelling caused a residential building to catch fire, which local responders say spread across an area of 200 square metres.