Officials in Sweden have vowed to determine why a man killed 10 people, and apparently himself, in an unprecedented attack that's shaken their "society to its core."

Sweden’s right-wing government said on Friday it would seek to tighten gun laws in the wake of the country’s deadliest mass shooting at an adult education center where the attacker appeared to have used several of his own licensed rifles.

Witnesses who survived Sweden’s worst mass shooting have described horror and panic that gripped an adult education center west of Stockholm as the gunman killed at least 10 people.