A gunman opened fire Wednesday morning at Annunciation Catholic School in Minneapolis, killing two students aged 8 and 10 and injuring 17 others, BBC reported.

The attack occurred during morning Mass, when the shooter, armed with multiple weapons, fired through the church windows before taking his own life. Fourteen of the wounded are children, with two in critical condition, according to police.

Governor Tim Walz said Minnesota is “heartbroken” and expressed support for the victims’ families. President Donald Trump ordered flags lowered to half-staff, pledging federal support.

The tragedy marks the fifth school shooting in the US this year, amid 286 mass shootings nationwide, according to BBC.