The gunman is also suspected in the killings of another man and his two-month-old daughter who were found last week shot dead in woods in a village outside Prague, the city's police chief, Martin Vondrasek, said on Thursday.
Authorities - who discovered a large arsenal of weapons at a downtown Prague Charles University building - were tipped off earlier on Thursday that the man was likely heading to Prague from his town in the Kladno region outside the capital with intentions of taking his own life.
Police and paramedics descended on the university building following the shooting. (AP PHOTO)
Shortly after that, the shooter's father was found dead.
Police evacuated an arts faculty building where the shooter was due to attend a lecture on Thursday afternoon, but then were called to the faculty's larger main building, arriving within minutes after reports of the shooting, Vondrasek said.
"We have very fresh unconfirmed information from an account on a social network that he was supposedly inspired by one terrorist attack in Russia in the autumn of this year," Vondrasek told reporters, adding the shooter was a legal holder of several firearms.
"It was a premediated, horrific act that started in the Kladno region and unfortunately ended here."
The gunman's death was likely a suicide but authorities are also investigating whether he might have been killed by police who returned fire, Vondrasek said.
"It was a premediated, horrific act," Prague police chief Martin Vondrasek said. (AP PHOTO)
Police said he was a high-achieving student with no criminal record, and he acted alone.
Police asked not to reveal the man's identity but his name reported by some Czech media matched a police search report.
Authorities sealed off the square and area adjacent to the faculty building, in a busy historical district down the hill from Prague Castle on a popular street leading to Old Town Square.
Media images showed students fleeing the building with their hands in the air, and others perched on a ledge near the roof trying to hide from the attacker while students barricaded classrooms with desks and chairs.
"We always thought that this was a thing that did not concern us. Now it turns out that, unfortunately, our world is also changing and the problem of the individual shooter is emerging here as well," Prague mayor Bohuslav Svoboda told Czech Television.
People gathered to light candles at the university in memory of the victims. (AP PHOTO)
The White House condemned the shooting and said the United States was ready to offer assistance.
Leaders across Europe including France's Emmanuel Macron offered their support.
Witness Ivo Havranek, 43, told Reuters via Zoom that he initially thought the "couple of bangs" he heard might have come from loud tourists or a nearby movie set.
"Then suddenly there were students and teachers running out of the building. I went through the crowd not realising what is actually going on. I wasn't ready to admit that something like that could happen in Prague," he said.
Only once he saw police officers with automatic rifles, he knew it was serious, he said.
I would like to thank for all the expressions of condolences and support to the people of the Czech Republic after today's shooting at the Faculty of Arts, Charles University. — Petr Fiala (@P_Fiala) It is very important for us in these difficult moments and we appreciate it very much.December 21, 2023
"They shouted at me to run."
Prime Minister Petr Fiala cancelled a trip to the east of the country and the government held an emergency meeting attended by President Petr Pavel and the head of the country's counterintelligence service.
Gun crime is relatively rare in the Czech Republic. In December 2019, a 42-year-old gunman killed six people at a hospital waiting room in the eastern Czech city of Ostrava before fleeing and fatally shooting himself, police said.
In 2015, a man fatally shot eight people and then killed himself at a restaurant in Uhersky Brod.
