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."

Despite his gunshot wounds, sustained Tuesday in Sweden's deadliest mass shooting, Salim Karim Iskef managed to video-call his fiancee to tell her he loved her one last time. The 28-year-old asked Kareen Alia to look after his mother and herself before the call ended.

"But this hate, it is coming from somewhere." A member of Kasselia's congregation, 29-year-old Salim Iskef, was among those murdered in Orebro on Tuesday in Sweden's first school shooting and the worst mass shooting in the country's history.