At least six people have been killed, 15 remain unaccounted for, and dozens more – most of them minors – have been injured in what President Vladimir Putin has described as a deliberate Ukrainian “terrorist attack” on a school dormitory in Russia’s Lugansk People’s Republic.

The attack on the main academic building and dormitory of the Starobelsk Professional College, which teaches students aged 14 to 18, was carried out in three waves, with 16 drones launched at the same target by the “neo-Nazi regime in Kiev,” according to Putin.

Governor Leonid Pasechnik said 86 students were inside the facility at the time of the attack, with at least 15 still unaccounted for and feared trapped under the rubble. Emergency services recovering the bodies had to pause operations at one point due to concerns over a Ukrainian “double-tap” strike.

Russia’s UN envoy, Vassily Nebenzia, told an emergency Security Council session that the strike was carried out “deliberately” at night, when the dormitory was full, to maximize the number of casualties.

Nebenzia accused Western diplomats of “turning a blind eye” to the crimes of the “neo-Nazi Kiev regime,” blasting their statements as “mockery” and “dancing on the bones” of the dead children.

READ MORE: Putin vows revenge for Ukrainian attack on school dorm