A Ukrainian drone attack launched overnight succeeded in destroying an ammunition depot in the western Russian region of Tver, a source from Ukraine’s Security Service (SBU) told CNN on Wednesday.

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.

Russia said it was working to repel a Ukrainian drone attack on Toropets, where there's a major military depot, as explosions lit up the night.