Memphis police officer shot, killed

SAN FRANCISCO (Reuters) - A police officer in Memphis, Tennessee, was shot and killed during a traffic stop on Saturday night, officials said.

Memphis Police Director Toney Armstrong told reporters that around 9:15 p.m. local time a citizen used the downed officer's radio to report he had been shot multiple times.

Armstrong said the officer was transported in critical condition to hospital, where he was later pronounced dead.

"This is a very difficult time," Armstrong said, adding that it was the third killing of a police officer in the past four years. "It doesn't get any easier."

The suspect remained at large, Armstrong said. He did not release the officer's name, pending family notification.

(Reporting by Curtis Skinner in San Francisco; Editing by Kim Coghill)