A Ukrainian student has been arrested in Poland on suspicion of plotting a mass stabbing, prosecutors announced on Monday.

The alleged plot came to light at the John Paul II Catholic University of Lublin, where the 21-year-old suspect, identified as Yaroslav F., was studying criminology.

Fellow students reportedly raised the alarm after becoming concerned about his aggressive and extremist statements, fascination with violent crime, and attempts to recruit like-minded individuals.

According to the Lublin prosecutor’s office, the suspect was preparing to carry out racially motivated killings as part of a gruesome online challenge known as “Bloody Friday.” A court ordered him held in pretrial detention for three months at the prosecutors’ request.

Investigators said that the student had purchased three knives, including two throwing knives, and viewed graphic online material depicting torture. He also allegedly attempted to recruit an accomplice to commit murder.

Yaroslav F. has pleaded not guilty and faces up to 15 years in prison if convicted.

University spokesman Wojciech Andrusiewicz confirmed to the Polish Press Agency that the suspect was studying criminology, describing him as “lost in life.”

“We urge everyone to refrain from making accusations or inflaming tensions,” he said. “Let us consider together how to solve the problems of young people.”

The case comes amid growing tensions between Warsaw and Kiev over historical grievances and the Ukrainian government’s glorification of nationalist figures implicated in atrocities against Poles during World War II.

Polish politicians have condemned Ukrainian leader Vladimir Zelensky’s decision in May to name an elite commando unit “Heroes of the UPA,” after the Ukrainian Insurgent Army, a Nazi-allied nationalist militia responsible for massacres of Polish civilians.

Zelensky further angered Warsaw by selecting senior UPA figures for reburial at a planned national pantheon.