A large-scale Ukrainian drone attack on Russia triggered an earthquake-sized blast at a major arsenal in the Tver region on Wednesday, forcing the evacuation of a nearby town, war bloggers and some media reported.

A “massive” Ukrainian drone attack sparked a giant blast in a Russian town suspected of housing an arsenal for missiles, ammunition and explosive, according to reports. The air strike on Toropets in the western part of Russia ’s Tver region also forced the partial evacuation of residents, regional authorities said on Wednesday.

Local authorities have partially evacuated residents of Toropets in Russia’s Tver Oblast after a mass drone attack overnight caused a large fire, Tver Oblast Governor Igor Rudenya claimed on Sept. 18.