The suspected gunman, who was among the dead, was named in media reports as Rickard Andersson, 35, a former student of the school who lived locally.

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".

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."