How Sweden’s worst mass shooting unfolded at a small town school - and why police have ‘no clear motive’ one week on - IN FOCUS: As Sweden falls silent for the victims of the Orebro killings their families are still waiting for answers,

A gunman who killed 11 people, including himself, at an adult education centre in central Sweden may have been a student at the school, police said on Thursday, as they described chaotic scenes after the country's deadliest mass shooting as being like an "inferno".

Five people have been shot at a school in Sweden as authorities warned the danger was not over while armed officers rushed to the scene. Armed police descended on the Risbergska School, an adult educational institute in the city of Örebro some 200 km (125 miles) west of Stockholm on Tuesday.

Swedish police said Sunday they were still struggling to establish the motive of the man behind the Scandinavian country's worst mass shooting, five days after the tragedy. A gunman killed 10 people on Tuesday after entering the Campus Risbergska, an educational centre for young adults in the town of Orebro, 200 kilometres west of Stockholm.

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."

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).