All Swedish schools and pre-schools will have to make plans to keep unauthorised people off their premises, the government said on Wednesday, as the country tries to come to terms with the worst school shooting in its history last week.

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.

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."

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.

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’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.

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.

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

A minute's silence was observed across Sweden on Tuesday to honour the victims of a deadly shooting at an adult education centre in the city of Örebro. The minute's silence was held in Örebro and several other Swedish cities at 12 pm (1100 GMT).