Investigators say a former student who killed nine students and a teacher in Austria a week ago and then took his own life had become fascinated with school shootings in recent years.

Austria plans to tighten its gun control rules after a 21-year-old killed 10 people then killed himself in the country's worst school shooting by far, the conservative-led government said on Wednesday.

Ten people were killed in a mass shooting at a high school in Graz, the country’s second-largest city, the police said. The suspect also died, in an apparent suicide.