Local authorities in the separatist stronghold, Donetsk, in east Ukraine say at least seven people have been killed after a barrage of artillery shells exploded near a busy bus stop.

The shells struck a trolley bus Thursday morning, instantly killing numerous passengers and blowing out the windows of a nearby building. With victims' bodies splayed across bus seats and pools of blood settled on its floor, the scene made for a gruesome sight.

Shopkeepers and local residents were in a state of shock when Mashable arrived shortly after the shells hit around 9:30 a.m. local time. A woman who said she lived on the top floor of the damaged building fought back tears as she described seeing the body of a neighbor, whom she had passed in her hallway that morning, riddled with holes form shrapnel.

"They are monsters!" cried Ludmila, a pensioner in her 70s who asked that her last name not be used.