Photo: The Canadian Press

Authorities on the Crimean Peninsula were searching for a possible accomplice of the student who carried out a shooting and bomb attack on a vocational school, killing 20 people and wounding more than 50 others, an official said Thursday.

An 18-year-old student, who later killed himself, was initially believed to be the only one to have been involved in the carnage at the Kerch Polytechnic College on Wednesday. Authorities haven't provided a motive for the shooting, and teachers and classmates described the attacker as a shy man who had few friends.

But Kremlin-appointed Crimean chief Sergei Aksyonov told Russian news agencies on Thursday that it is possible that the attacker, identified as Vyacheslav Roslyakov, had an accomplice.

"The point is to find out who was coaching him for this crime," he said. "He was acting on his own here, we know that. But this scoundrel could not have prepared this attack on his own, in my opinion and according to my colleagues."

Residents of the Black Sea city of Kerch brought flowers and toys to a makeshift memorial outside the school on Thursday morning. Many were in tears and struggled to speak.

Russia annexed the Crimean Peninsula from Ukraine in 2014. Wednesday's attack was by far the worst by a student in Russia, raising questions about school security in the country. The Kerch Polytechnic College had only a front desk with no security guards. Russia's National Guard said Thursday that it has deployed officers and riot police to all schools and colleges in Kerch in the aftermath of the attack.

The death toll from the shooting climbed by one to 20 on Thursday after one of the wounded died in a hospital, and the first victim will be buried later in the day.

Dozens remain hospitalized in Kerch, and at least 10 people with severe injuries will be airlifted to top Russian hospitals for surgery, Health Minister Veronika Skvortsova said.

Most of the people killed died from gunshot wounds, and those who ended up hospitalized have injuries from a blast from an improvised explosive device that was packed with shrapnel.