A man walking on the U.S. Highway 101 was shot by a San Francisco police officer Thursday after threatening the officer with an edged weapon, the department said.

The shooting was reported at about 11:19 a.m. at Highway 101 at the Cesar Chavez Street / Potrero Avenue offramp from northbound Highway 101 adjacent to Bayshore Avenue.

The Police Department said officers were assisting sheriff's deputies regarding a male subject walking on the freeway, and made contact with the person near the Cesar Chavez offramp. 

"During the encounter, the subject produced an edged weapon, and an officer-involved shooting occurred," a police statement said. "One SFPD officer was involved."

The San Francisco Fire Department said a crew transported a person to a hospital with life-threatening injuries. His current medical condition was not known, police said. No one else was injured.

The number 4 and 5 lanes of northbound Highway 101 were closed near the scene, as was the Cesar Chavez / Potrero exit during the investigation. There was no estimated time of reopening.

Aside from the police investigation, the department said the shooting would be investigated by its internal affairs division, the District Attorney's Office, and the city's Department of Police Accountability.

Police said a town hall meeting about the shooting would also be held within 10 days.

Anyone with information about the incident was asked to contact the Police Department at (415) 575-4444 or send a text to TIP411 and begin the message with SFPD.