President Petr Pavel of the Czech Republic has declared a day of mourning after a 24-year-old student shot dead his father, before killing 14 people and wounding 25 others at Charles University in Prague.

President Petr Pavel declared after a special cabinet meeting, that December 23 would be a day of mourning with flags on official buildings to be flown at half-mast and people asked to observe a minute’s silence at noon.

“I would express my great sadness along with helpless anger at the unnecessary loss of so many young lives,” Pavel said.

He added, “I would like to express my sincere condolences to all relatives of the victims, to all who were at this tragic incident, the most tragic in the history of the Czech Republic.”

The shooting, deemed the country’s worst-ever mass shooting, occurred on Thursday afternoon at the Charles University’s Faculty of Arts.

Media images showed students evacuating 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.

“I can confirm 14 victims of the horrible crime and 25 wounded, of which 10 seriously,” police chief Martin Vondrasek told reporters after the shooting.

Vondrasek disclosed that the gunman, previously unknown to the police, had a large number of legally owned weapons and that swift police action after a tip-off earlier in the day had prevented even worse carnage.

Police evacuated a Faculty of Arts building where the gunman was due to attend a lecture, but were then called to the faculty’s larger main building, arriving within minutes after reports of the shooting, Vondrasek said.

Police had “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, describing the attack as a “pre-mediated horrific act.”

Authorities did not name the gunman but said that he was a high-achieving student with no prior criminal record.

His death was probably a suicide, but authorities were also investigating whether he might have been killed by police who returned fire.

All the victims were killed inside the building, Vondrasek added. Media reports said at least some of them were the gunman’s fellow students.

The Dutch Ministry of Foreign Affairs said one of the injured was a Dutch national.

Charles University Mourns The Dead

In a statement, Charles University said, “We mourn the loss of life of members of our university community, express our deepest condolences to all the bereaved, and our thoughts are with all those affected by the tragedy.”

People lit candles outside the university.

Prime Minister Petr Fiala said that the “lone gunman … wasted many lives of mostly young people.”

“There is no justification for this horrendous act,” he added.

United States’ President Joe Biden condemned the “senseless” attack and the White House said the U.S was ready to offer assistance.

French President Emmanuel Macron expressed his “solidarity” with the Czech people, as did other European leaders including EU chief Ursula von der Leyen and Ukrainian President Volodymyr Zelenskyy.