Rescuers working at the site of a damaged dormitory building following a reported Ukrainian drone strike in Starobilsk, Luhansk region, Russia. According to Russian authorities, at least 18 people were killed and dozens of others injured in the attack. Photo by Russian Emergency Ministry Press Service/EPA

May 23 (UPI) -- A Ukraine drone hit a Russian dormitory killing at least 18 overnight in Starobilsk in the Luhansk region, Russian President Vladimir Putin said Saturday.

But Ukraine's military said it hit a military drone unit target.

There were 42 others injured, and three other people may be trapped under rubble, the BBC reported.

Putin called the attack a "terrorist strike," and said the hit was deliberate, Al Jazeera reported.