MOSCOW—The religious Orthodox school that was targeted by a Russian teenage bomber had previously been described as a “hellish” and “damaging” place by students who had attended it and parents who had enrolled their children there.

On Monday morning, 18-year-old Vladislav Struzhenkov, a graduate of the high school in the small town of Serpukhov near Moscow, returned to his former campus to detonate a bomb, injuring himself and at least 12 students.

The bomber’s age and name were first published on the Baza Channel Telegram account. The teenage bomber reportedly brought the explosive device to the school a few minutes before students gathered for morning prayer. The bomb went off at 8:26 a.m. local time, right by the school’s entrance, on the grounds of the 14th-century Vladychny convent.

There are only two comments from students on the school’s Yandex page, which is the Russian equivalent of Google. “I study here, I am bullied by teachers; the food is horrible, relations are terrible, hope they close this hellish place,” one user wrote in November. Another comment posted last year compared the school’s rector to “El Picador” and added: “Welcome to our steam room,” a reference to a Russian idiom which suggests the school engages in brainwashing.

One parent told Andrei Kurayev, protodeacon of the Russian Orthodox Church who spoke with The Daily Beast on Monday, that the institution was “the worst school” his children had ever attended. “[I] believe my children were badly damaged there,” he wrote to Kurayev.

Responding to The Daily Beast’s request for a phone interview with the convent’s head nun, Mother Klavdi, a member of the convent said: “The young man with bomb has died, tragically. The Mother did not bless us to give any more comments.” On Monday afternoon, official reports denied that Struzhenkov had died. The attacker reportedly lost his leg in the explosion, and doctors are still fighting to save him in an intensive care unit.

The school is about 300 meters away from the doors of the convent, which is home to some 40 nuns. Terrified by the explosion, schoolkids ran to the convent courtyard in the freezing cold without their winter coats. Ambulances later rushed eight wounded students to hospital.

“This is a shockingly sad tragedy. We have seen attacks by suicide bombers on Russian state institutions for many years but most of them were performed by members of radical Islamist groups and not by Orthodox believers,” Oleg Orlov, the chair of Memorial, Russia’s leading human rights organization, told The Daily Beast.

Religious schools are known to be tough on Russian students. Interfax news agency reported that the suspect was “believed to have been motivated by his hatred of the teachers and nuns.”

But how did the provincial teen build the explosive device?

“His father was a mechanic, he fixed automobiles. The rest is a typical Columbine story—teenagers suffering from bullying discuss such attacks in chats on social media,” protodeacon Kurayev said. “Nobody pays attention to teenage issues in Russia,” he added, explaining that he was not surprised that the bomber had reportedly complained about bullying and humiliation at the school.

Struzhenkov’s school has a list of strict rules for students on its official website, including a ban on running and yelling on campus. “Fear all self-will like fire, do everything with the permission of adults,” one excerpt from the site reads. The rules demand that every high schooler “show respect and attention to his mentors/teachers, obey them without wrangling, and be diligent and hardworking. In case of offense, humbly accept the well-deserved punishment.”

Attacks on schools by current and former students have been plaguing Russia since 2014, with many using knives, explosives and guns to carry out violent plans. In May, eight students and one teacher were killed at a school in the city of Kazan by a 19-year-old shooter, Ilnaz Galyaviyev. The attacker was wearing a mask with the word “God” printed on it.

As for the Serpukhov bomber, Kurayev does not believe that the young man was deeply religious. The deacon insists that some monastery schools are just “a space for experiments on children.” He added: “I think he [the bomber] became allergic to all the self-praise and hypocrisy at his school.”

Some reports said that Struzhenkov had serious health issues with his thyroid, which would trigger mood swings. “I would never say that, this is not true, he was a good athlete, a calm boy; but I saw him the last time in 2018,” Struzhenkov’s former coach Philip Savostin told The Daily Beast in a phone interview on Monday.

Pro-Kremlin political technologist Sergei Markov told The Daily Beast that he believes there’s a solution to the epidemic of school violence that is sweeping Russia.

“There is a good rule in the army: Soldiers should be busy every minute,” Markov said, advocating for even stricter state control over teenage life. “When they are not, like in the case with this bomber, officers have lots of headaches.”