Flags flew at half mast at the royal palace in Stockholm, after a shooting at a community education centre in Orebro left 11 dead. The Prime Minister called it a dark day for all of Sweden, and was joined by the king and queen at a church service in honour of the victims.

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.

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 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.

Sweden's worst mass shooting left at least 11 people dead, including the gunman, and at least five seriously wounded at an adult education centre west

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.

Survivors of Sweden's worst mass shooting on Wednesday recalled trying to save the lives of their comrades at a school for adults in Örebro, a day after a gunman killed 11 people on what the prime minister called a "dark day" in the country's history.