Austria's chancellor says his country will toughen its gun laws after a 21-year-old former student killed nine students and a teacher at his school last week in what's considered the Alpine country's deadliest post-war attack.

A defense official said the man, 21, was turned down for military service after failing a psychological test. Investigators are asking how he passed another such test to obtain a gun permit.

Speaking to ORF radio, Stocker said officials aimed to set stricter eligibility rules for possession and purchase of arms after a 21-year-old Austrian man on Tuesday shot dead ten people at a high school in the city of Graz before killing himself.