Minneapolis Police Chief Brian O’Hara told a media briefing that the shooter, in his early twenties, sprayed bullets into the Annunciation Church as dozens of students were at Mass to celebrate their first week back to school.

The church sits next to an affiliated school in the south of the city, the largest in the state of Minnesota.

“Two young children, ages eight and 10, were killed where they sat in the pews,” O’Hara said, adding that 17 others were injured, including 14 children.

Two were in critical condition, he said.

The gunman fired a rifle, shotgun and pistol before he took his own life in the parking lot, according to the police chief.

Minnesota Governor Tim Walz wrote on X earlier that he was “praying for our kids and teachers whose first week of school was marred by this horrific act of violence.”

Live video footage showed panicked parents retrieving their young children and fleeing, amid a major emergency response.

“This was a deliberate act of violence against innocent children and other people worshipping. The sheer cruelty and cowardice of firing into a church full of children is absolutely incomprehensible,” O’Hara said.

“Our hearts are broken for the families who have lost their children, for these young lives that are now fighting to recover, and for our entire community that has been so deeply traumatised by this senseless attack,” he added.

Wednesday’s violence is the latest in a long line of school shootings in the United States, where guns outnumber people and attempts to restrict access to firearms face perennial political deadlock.

“Don’t just say this is about thoughts and prayers right now. These kids were literally praying. It was the first week of school. They were in a church. These are kids that should be learning with their friends,” Minneapolis Mayor Jacob Frey told reporters.

“They should be playing on the playground. They should be able to go to school or church in peace without the fear or risk of violence.”

President Donald Trump said he had been briefed on the “tragic shooting” and that the FBI was responding.

“The White House will continue to monitor this terrible situation. Please join me in praying for everyone involved!” he wrote on his Truth Social platform.

The confirmed shooting comes after a wave of false reports of active shooters at US college campuses around the country as students return from summer break.