A police officer and a murder suspect were killed after an altercation during questioning escalated to gunfire at police headquarters in Jackson, Mississippi, authorities said on Thursday.
The officer was identified as Detective Eric Smith.
"This is indeed a sad day for our city, a sad day for the Jackson Police Department," said Jackson Mayor Harvey Johnson in a filmed interview posted on the Jackson Clarion-Ledger website.
"Our hearts go out to the Smith family. Detective Smith was an excellent officer, from all reports... Obviously the men and women of the Police Department are taking this pretty hard."
Smith leaves a wife and two sons, Johnson said on his Facebook page.
Hinds County Sheriff's Office spokesman Othor Cain said the shooting occurred on the third floor of the police headquarters in downtown Jackson.
"During an interview with the suspect, an altercation ensued and shots were fired resulting in the officer being shot and the suspect," Cain said. "Both have been pronounced dead."
It was not clear if the gun used in the shooting belonged to the officer.
Cain could not identify either of those killed. He said the officer was a veteran with the police department who had served for more than a decade.
The shooting occurred amid a heightened scrutiny of attacks on U.S. law enforcement officials after two prosecutors from Kaufman County, Texas, and the Colorado prisons chief were all killed in what appeared to be targeted attacks this year.
A West Virginia sheriff was also shot to death while sitting in his police SUV on Wednesday eating his lunch.
The Mississippi Bureau of Investigation has sent investigators to the Jackson crime scene, according to spokesman Warren Strain.