According to a tweet from the senator, the assault occurred Monday in Jack London Square. The suspect pushed her in the back, took her cell phone and then jumped in a "waiting car," according to the tweet.
"She is thankful that she was not seriously injured," the tweet read.
LISTEN: Full phone interview with Barbara Boxer on assault, robbery in Oakland
PHONE INTERVIEW: Barbara Boxer recounts attack near Oakland apartment
Police managed to track the phone to San Francisco and officers were searching the area of Bush and Kearny Streets.
The Oakland Police Department and Crime Stoppers of Oakland are offering up to $2,000 reward for information leading to an arrest in the case.
In a statement Monday night, a spokesperson said Oakland Mayor Libby Schaaf was "troubled' to learn about the incident.
"The Mayor was deeply troubled to learn of the assault and robbery of Sen. Boxer today. She spoke with the Senator's family to extend her well wishes for a speedy recovery and was relieved to learn she was not seriously injured. OPD is investigating the incident and is working to collect any surveillance images from the area that will assist in their investigation," said spokesperson Justin Berton.