Oct. 18 (UPI) -- A 20th person died Thursday as a result of a mass shooting and explosion at a school in Crimea, said authorities, who are working to determine whether the student suspect plotted the attack alone.
Crimean Prime Minister Sergey Aksyonov said the shooter, identified as 18-year-old student Vladislav Roslyakov, couldn't have planned the entire crime on his own, Russia's state-run Tass news agency reported.
"The fact that he acted alone at the scene is understandable. My colleagues and I believe, however, that he could not have plotted all the preliminary details all by himself," he said.
Investigators initially treated the shooting as a terrorist attack, but have since reclassified it as "mass murder" as they attempt to determine Roslyakov's motive, ABC News reported.
Crimea, internationally recognized as part of Ukraine, was annexed by Russia in 2014. Since then Ukraine has been accused of sending agents to blow up infrastructure in Crimea.
Some in Russia have suggested Ukraine may have played a role in the attack, but no evidence supporting the allegation has been found.
Roslyakov's father told police his son had an interest in weapons and had recently broken off contact with one of his few close friends.
Officials said Roslyakov obtained his gun license, required to own a firearm, about two months ago and security camera footage showed him buying shotgun shells four days before the shooting.
Witnesses said Roslyakov tossed explosives into classrooms and opened fire on students during the attack at Kerch Polytechnic College on Wednesday.
He killed 20 people and killed himself after the attack. Kerch officials said at least 42 people who were injured in the attack were still hospitalized, including six who were in critical condition.
Russian Health Minster Veronika Skvortsova said most of the victims were killed by gunfire, while others sustained injuries from metal objects that were lodged into their bodies due to the explosions.
"The children's muscles are all 'minced,' basically, with small pieces of metal," Skvortsova said. "We have found nuts and metal balls in the liver, guts and blood vessels of those whose internal organs were ruptured. This is how powerful the explosion was."
Aksyonov said Kerch Polytechnic College would reopen Monday, while Russia's National Guard placed armed guards around all schools and daycare centers throughout Kerch.
"Today, all pre-school [institutions] and schools have been put under the protection of Russian National Guard fighters. All 21 schools and 20 daycare centers without exception are being guarded from 7 a.m.," he said.