KERCH, October 18. /TASS/. The college student who carried out a mass shooting and explosion attack at a vocational institute in the Crimean city of Kerch could not have plotted the entire incident single-handedly, Crimea’s head Sergei Aksyonov told reporters on Thursday.

"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 asserted.

According to Aksyonov, Russia’s National Guard had placed armed guards around all schools and daycare centers throughout Kerch in the wake of the tragedy.

"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 7am," he stated.

Crimea’s head added that the Kerch Polytechnic College where the attack occurred on Wednesday, would reopen on Monday, October 22.

"We are dealing with [the tragedy’s] aftermath. The college will resume its work on Monday [October 22]," he said.

Meanwhile, Dilyaver Melgaziev, Deputy Head of the Kerch Municipal Administration, informed TASS that security had been beefed up at the city’s social infrastructure facilities, adding that the campus of the Kerch Polytechnic College continued to be cordoned off.

On Wednesday, a local student, armed with a rifle, went on a shooting rampage and detonated a bomb on the campus of the Kerch Polytechnic College in Crimea. The shooter later turned the gun on himself and committed suicide. Subsequently, a criminal case was initially opened on terrorism charges, but was later reclassified as murder.

Twenty-one people died because of the shooting and explosion at the Kerch technical college, including the gun-wielding teenage attacker who ended up taking his own life. Around 50 people were taken to local hospitals, with ten of them in intensive care units in grave condition.

Three days of mourning have been declared in Crimea as of Thursday.