Three children were killed when an assailant opened fire at an elementary school in Nashville, Tennessee, on Monday, according to officials and media reports.

The city’s police reported “an active shooter event” at The Covenant School on Twitter, saying the shooter had been killed in an exchange with police.

The Nashville Fire Department confirmed “multiple patients” with media including NBC and The New York Times citing a hospital spokesperson confirming three children had been killed.

“Three pediatric patients were transported to Monroe Carell Jr. Children’s Hospital at Vanderbilt, all having suffered gunshot wounds,” Vanderbilt University Medical Center spokesperson John Howser was quoted as saying. “All three were pronounced dead after arrival.”

The Covenant School is a private Christian institution with students in preschool to roughly age 12.(AFP)