A male suspect was shot by at least one Border Patrol agent near San Diego, Calif., early Sunday after attacking a separate agent who had been driving an all-terrain vehicle in a remote region near Imperial Beach, according to U.S. Customs and Border Protection and the San Diego Police Department.

An "agent" had been operating an ATV near Spooner's Mesa, a mountain located half a mile north of the border, when he was assaulted around 2:30 a.m. Pacific time, SDPD said in a statement provided by email Monday.

SDPD said one agent was knocked off his vehicle after being hit by a rock. The agent's ATV was then stolen by the assailant.

However, CBP, a component of the Department of Homeland Security, said multiple "agents" were initially assaulted.

Other agents in the vicinity were alerted to the attack and chased the suspect on their ATVs down Monument Road in Imperial Beach and two agents fired shots at him. He was struck by at least one bullet and crashed his stolen vehicle into a fence, according to the police department.

"Border Patrol agents discharged their service issued weapons, striking the subject. Emergency Medical Services (EMS) were contacted and the man was taken to a nearby hospital for treatment," CBP said.

The unnamed suspect was described as a 19-year-old male, SDPD said. He was taken to a local hospital and treated for non-life-threatening injuries.

The FBI, SDP, CBP's Office of Professional Responsibility, and the San Diego Border Patrol Sector are investigating the assaults and use of force by the agent.

The Border Patrol agent who was attacked was not seriously injured.

The use of force incident, CBP's term for when an agent uses his or her gun, is rare. The agency reported 17 such occurrences in fiscal 2017.