Ten people are dead and 28 injured after a gunman opened fire at a school in the southern Austrian city of Graz on Tuesday. Authorities say the attacker, a 22-year-old former student, entered the building armed with a pistol and a shotgun before targeting two classrooms.

The attacker reportedly began the assault by storming his former classroom, firing indiscriminately. Several students and one adult were killed. The shooter later turned the gun on himself, according to police.

Officials confirmed that four of the 28 wounded are in critical condition, with several victims suffering gunshot wounds to the head.

Austrian Chancellor Christian Stocker called the attack a “killing spree” and described it as a “dark day” for the country.

“This senseless act of violence has shaken our nation. Our thoughts are with the victims, their families, and all those affected,” Chancellor Stocker said in a statement.

Emergency services and armed police responded quickly to the scene. The school has been evacuated, and trauma teams are working with survivors and their families.

Authorities are now investigating the shooter’s background and possible motives. Early reports suggest he may have struggled with mental health issues and had legally obtained at least one of the firearms.

The Graz attack marks one of the deadliest school shootings in Austrian history and has reignited debate over gun laws and school security across the country.