GRAZ, Austria: Austria is reeling after a tragic school shooting in Graz that left ten people dead, including the gunman, and 12 others injured — the deadliest such incident in the country's modern history.

Authorities said the shooter, a 21-year-old former student, entered the secondary school this week armed with a pistol and a shotgun, opening fire in two classrooms before taking his own life in a bathroom. His motive remains unclear.

Six of those killed were female, and three were male, said Interior Minister Gerhard Karner. The Austrian Press Agency (APA) later reported that a tenth victim, a young woman, died in hospital from her injuries. Most of the victims were believed to be students, though officials did not release their identities.

"The rampage at a school in Graz is a national tragedy that has deeply shaken our entire country," said Chancellor Christian Stocker, calling it a "dark day in the history of our country."

"There are no words for the pain and grief that we all — all of Austria — are feeling right now."

More than 300 police officers responded to the school shortly after shots were heard around 10 a.m. Emergency services arrived within minutes and cordoned off the area while family members of the victims were offered support on-site.

Local media reported that the shooter had previously attended one of the classrooms attacked. The Salzburger Nachrichten said the gunman may have been a victim of bullying, though this has not been officially confirmed.

Austrian newspaper Kronen-Zeitung reported that police searching the shooter's home found a farewell note. No details were released about its contents.

Police said they believe the shooter acted alone. "Extensive criminal investigations are still required," a police spokesperson said, adding that they could not yet speculate on a motive.

The shooting stunned the nation. Austria, known for its low violent crime rate, has little experience with large-scale school violence. Experts described the attack as the worst of its kind in post-war Austrian history.

"This is deeply shocking," said Julia Ebner, an extremism expert at the Institute for Strategic Dialogue. "School shootings are sporadic in Austria, especially compared to countries like the United States."

German Chancellor Friedrich Merz was among international leaders who expressed condolences. "We hope that their loved ones can find comfort in the company of their families and friends in this dark hour," he said.

Though Austria has strict gun laws, it also has one of Europe's highest rates of civilian gun ownership — about 30 firearms per 100 people, according to the Small Arms Survey.