In a Thursday statement, Qassemi also offered sympathy to the survivors and bereaved families of the tragic incident’s victims.
At least 19 people have been killed and dozens more wounded in a shooting at a college in Russian-annexed Crimea.
An 18-year-old student ran through the Kerch technical college firing at fellow pupils before killing himself, Russian investigators say.
Witnesses have also spoken of at least one blast caused by an unidentified explosive. The motive is unclear.
The alleged perpetrator, named Vladislav Roslyakov, is said to have run from room to room as he fired, starting in the area near the canteen. He then shot himself dead, Russia’s investigative committee said.
