Manhunt after US police officer shot dead

A police officer was shot dead during a traffic stop in Memphis and a manhunt launched for the killer, Tennessee police said Sunday.

Sean Bolton, 33, who had been with the Memphis Police Department (MPD) since October 2010, suffered multiple gunshot wounds in Saturday's incident.

He was rushed to a hospital in critical condition but died of his injuries.

"On August 1, 2015 at approximately 9:18 pm Communications was alerted by a citizen through one of our officer's radios that an officer had been shot in the area of Perkins and Cottonwood," a police statement said.

"Once officers arrived on the scene they located an MPD Officer who had been shot during what appeared to be a traffic stop.

"The suspect responsible is still at large and officers are in the area attempting to locate him."

The incident comes just days after a white Ohio policeman who shot a black man during a traffic stop pleaded not guilty to murder charges, the latest in a string of incidents that have heightened racial tensions in the United States, particularly in relations between police and black Americans.

There was no immediate suggestion that the fatal Memphis shooting was linked to the Ohio incident or other cases.

Memphis Mayor A.C. Wharton told local media: "We ask prayers for the family, we ask prayers for this officer's fellow officers and just for our city as a whole."