Images on social media showed students barricaded in classrooms, people running through the streets and emergency vehicles and armed police swarming a square in Prague’s historic old town just yards from the Vltava River that winds through the medieval city.

Police revised their original tally of “more than 15” dead to 14 at a news conference late Thursday.

Around 25 people were injured, 11 of them seriously, Prague’s emergency response service said on X, formerly Twitter. The shooter was a student at the university, and police think he killed his father earlier in the day in a town near Prague, Vondrasek said. After searching his home, they also think he might be connected to a killing last week of a man and his 2-month-old daughter.

“We have no information at this time that the perpetrator is connected to any terrorist organization,” police said Thursday night on X. Police had completed a sweep for explosives and were identifying victims. Embassies would be contacted if foreigners were among the dead, police said. A representative for the U.S. Embassy in Prague declined to comment.

The mass killing is one of the worst in Europe since 130 people were killed in the Bataclan terrorist attack in Paris in 2015, which the Islamic State later claimed responsibility for. On Thursday, Prague police said multiple guns were found at the site. They did not identify the shooter but said he had obtained the weapons legally.

The Czech Republic has more permissive gun laws than most countries in Europe, even allowing concealed carry with a permit. Still, the country requires citizens to take strict tests before being able to obtain weapons. Mass killings are rare but not unheard of. In 2019, a gunman killed six people and himself at a Czech hospital in the eastern city of Ostrava. In 2015, a gunman shot eight people and himself in the town of Uhersky Brod. Thursday’s killings are the worst in the country since Czechoslovakia split up into Czech Republic and Slovakia at the end of 1992, according to Agence France-Presse.

Leaders from around the continent and the world expressed shock and sorrow Thursday.

“The president and the first lady are praying for the families who lost loved ones and everyone else who has been affected by this senseless act of violence,” White House spokesperson Karine Jean-Pierre said at a news briefing. “Federal authorities are in touch with Czech authorities as they investigate this incident.”

Charles University, founded in 1348 and named for the Holy Roman Emperor Charles IV, is the largest and most prestigious university in the Czech Republic. Twenty percent of its more than 49,000 students come from abroad, including many from the United States. Its buildings are spread throughout the city rather than being concentrated in a central campus. The university’s Faculty of Arts is next to the square where the shooting took place.

“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, according to Reuters.

Czech President Petr Pavel said he was “shocked” by Thursday’s shootings.

“I would like to express my deep regret and sincere condolences to the families and relatives of the victims claimed by the shooting,” Pavel posted on X.