Earlier, Kronen Zeitung newspaper reported that at least eight people were confirmed dead, with ten others in critical condition.
Although police did not immediately release an official toll, they confirmed that several people had died in the attack.
The victims’ identities and the number of pupils among the deceased have not been confirmed.
Emergency services responded quickly, and ambulances were seen outside the school building.
The motive for the shooting remains unclear, and investigations are ongoing.
