A gunman opened fire at an adult education center in the Swedish city of Örebro on Tuesday, killing at least 10 people in what the country’s prime minister called the “worst mass shooting in Swedish history.

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.

The gunman was among the 11 people killed in the worst shooting in the history of Sweden at an adult education centre west of Stockholm. On Tuesday, police received reports of a shooting in Orebro, a city 200km (124 miles) west of Stockholm, at 12.33pm local time and engaged in an exchange of bullets with the suspect.