A spectator has been killed after he was accidentally struck by a hammer thrown by an athlete at a high school indoor athletics event in the United States.

The incident occurred on Sunday during the competition at the University of Colorado Colorado Springs campus.

A spokesperson for the university said a spectator "was killed when a hammer thrown by a participant cleared certified barriers and struck him".

The man who died, named by El Paso County Coronor's office as Wade Langston, 57, was the father of a competitor and reportedly died, external while shielding his wife and son from the hammer, which can weigh up to 7.26kg (1st 2lb).

"We are heartbroken at this horrible accident and are focused on supporting all involved," said University of Colorado Colorado Springs chancellor Jennifer Sobanet.

A spokesperson for the Colorado Springs Police Department did not comment, beyond saying it was a "non-criminal incident".