New Delhi, Aug. 27 -- A gunman opened fire during Mass at Annunciation Catholic School in Minneapolis on Wednesday, killing two children and injuring 17 others before taking his own life, authorities said.

Police Chief Brian O'Hara said the suspect, a man in his early 20s armed with a rifle, shotgun, and pistol, approached the side of the adjoining church and fired through windows at children seated in the pews. Fourteen of the injured are children, including two in critical condition.

"The shooter targeted kids as they prayed," O'Hara told reporters. "This is one of the darkest days this city has ever seen."

The suspect, who died by suicide inside the rear of the church, has not been publicly identified. O'Hara said he did not have an...