Authorities warned that the death toll was likely to rise.
The suspect, identified by Czech police—who use crime suspects' first names and last initials—as David K., was reportedly a 24-year-old world history student at the university. The New York Timesreported that he fatally shot himself in addition to the victims.
On social media, several users posted a photo of students clinging to a ledge on one of the school buildings as they tried to evade the shooter.
A police officer with Interpol Prague also reported that the suspect shot and killed his father in a town outside Prague before proceeding to the university.
The authorities were investigating late Thursday whether several violent messages posted in recent days by someone using the name David Kozak on the platform Telegram were connected to the shooting. One of the messages suggested that two mass shootings that took place in Russia earlier this month and in 2021 had inspired Thursday's shooting.
The Czech Republic restricts gun ownership by requiring stringent testing of people who try to buy firearms, but the government has less strict gun laws than most other European countries.
The country recognizes the "right to acquire, keep, and bear firearms" and the constitution was amended in 2021 to legally guarantee "the right to defend one's own life or the life of another person with a weapon."
Police said the gunman legally owned several firearms, as did the 63-year-old man who shot and killed eight people in a restaurant in an eastern town in 2015.
