Government offices, schools and workplaces fell silent in Sweden at midday on Tuesday in remembrance of the victims of a mass shooting at an adult education centre last week when a gunman killed 10 people before turning his weapon on himself.

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."

The king and queen visited the scene of the tragic event that occurred on Tuesday and Swedish flags were flown at half-mast to honor the victims.

Badly wounded, Salim Karim Iskef managed to video-call his fiancée to say he loved her one last time before he died in Sweden's deadliest mass shooting.

The police responding to the attack encountered firing so intense that they struggled to tell how many gunmen were on the scene, an official said.

Sweden is set to tighten its gun laws, including a ban on certain semiautomatic weapons, after a mass shooting that left 11 people dead.

Sweden's worst mass shooting left at least 11 people dead, including the gunman, and at least five seriously wounded at an adult education center west of Stockholm. The gunman's motive hadn't been determined by early Wednesday as the Scandinavian nation — where gun violence at schools is very rare — reeled from an attack.

The shooter targeted a center that serves migrants seeking to integrate into a country that had already reversed its liberal migration policies.

Sweden is reeling from the country's deadliest mass shooting this week as investigators continue to look into the gunman's motive.