(Reuters) - A Denver police officer was shot and killed on Sunday after trying to break up a fight during a free jazz concert in a city park, police said.

Police responded to a call shortly after 8 p.m. MDT (0200 GMT on Monday) about a disturbance at the outdoor concert. An officer was shot in the head while attempting to break up a fight between two groups, police said. The officer was later pronounced dead.

The Denver Post reported that concert-goers fled in panic, abandoning lawn chairs and blankets brought out for what was to be a laid-back tribute to Charlie Burrell, a local classical and jazz bassist for the Denver Symphony Orchestra.

"At first, we thought it was someone setting off fireworks," Dave Sevick wrote on the City Park Jazz Facebook page, "until, three seconds later, we heard the screams and saw the hordes of people running towards us."

Police had no further details on the incident.

(Reporting by Mary Slosson; Editing by Cynthia Johnston and Paul Simao)