The postal worker is being treated at Highland Hospital and is in stable condition.
Oakland police are investigating this shooting, along with the U.S. Postal Service, who says it is a federal crime.
An Oakland police spokesperson confirmed there were multiple rounds fired and bullets went through the postal vehicle. What's not clear is why the driver was shot.
"We can't speculate at this time if she was or she wasn't the target of the shooting," Oakland Police Dept. Ofc. Marco Marquez said.
"This is a serious crime that we have a standing $50,000 reward. If anybody has any information, we'd like them to contact either the Oakland Police Department or postal inspectors," U.S. postal inspector Jeff Fitch said.
The postal worker was shot in her hip and is currently in stable condition at Highland Hospital.
As of right now, her name is not being released.