At least four people were killed and ten others injured in a mass shooting at a child's birthday party in Stockton, California on Saturday evening. The incident took place at a restaurant in the northern California city shortly before 6 p.m. local time. The suspect is still on the loose. Police believe the shooting may have been "targeted," though the exact motives remain unclear. Victims include both adults and children. The condition of the injured has not yet been confirmed. San Joaquin County Sheriff’s Office spokesperson Heather Brent called the event "unfathomable" and said the investigation is very active and ongoing. "Early indications suggest this may be a targeted incident, and investigators are exploring all possibilities," the statement read. Detectives are working to understand what led to this tragedy. Stockton's vice mayor Jason Lee expressed his grief and anger on social media. He said, "I am devastated and angry to learn about the mass shooting at a child's birthday party. A birthday party should never be a place where families fear for their lives." California Governor Gavin Newsom was briefed on the "horrific shooting" and is closely monitoring the situation.