Eleven people injured in a school shooting in Graz, Austria, on Tuesday are still being treated but are not in life-threatening condition, officials said.

Students were sitting in their classrooms at a secondary school in Graz when a 21-year-old Austrian man shot dead nine people, before killing himself. Twelve people were injured in Tuesday morning's violence,

King Charles and Queen Camilla have sent an emotional message to Austria following the shooting rampage in Graz.

"I think the first thing is shock, to be honest. I think you can't react the other way. I think everyone in the school is in complete shock," said 24-year-old student Helene Parr, who knows people at the BORG Dreierschützengasse school, where the mass shooting took place.

King Charles has expressed profound sorrow following Tuesday's devastating school shooting in Graz, Austria, which claimed 11 lives. The attack at Dreierschützengasse secondary school represents Austria's deadliest school shooting in recent memory.