A Minneapolis Catholic school's been left devastated after a gunman killed two children and injured 17 other people. 

He was armed with a rifle, shotgun, and pistol, and shot through the church windows before turning a gun on himself.

Annunciation Catholic School was marking their first week of school with morning mass and had highlighted their theme for the year as 'hope'. 

US Correspondent Toni Waterman told Ryan Bridge the shooter doesn’t have an extensive criminal history, despite showing up fully armed. 

It’s unknown what the motive was at this stage. 

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