Part of Vice President JD Vance’s security detail was hit by shrapnel from a shell that detonated prematurely during a Marine Corps event in California, according to a report.

The New York Times reported that a 155-millimeter shell fired during a live demo at Camp Pendleton on Saturday for the Marine Corps’ 250th anniversary prematurely detonated, dropping fragments on a motorcycle part of Vance’s motorcade and a California Highway Patrol vehicle.

The California Highway Patrol said in a statement that metal shrapnel from an explosive device fired over Interstate 5 detonated overhead.

“This was an unusual and concerning situation,” CHP Border Division Chief Tony Coronado said. “It is highly uncommon for any live-fire or explosive training activity to occur over an active freeway. As a Marine myself, I have tremendous respect for our military partners, but my foremost responsibility is ensuring the safety of the people of California and the officers who protect them.”

The Marine Corps suspended firing and no injuries were reported.

The First Marine Expeditionary Force at Camp Pendleton said it has launched an investigation into the incident.

“The demonstration went through a rigorous safety evaluation, and deliberate layers of redundancy, to ensure the safety of fellow citizens,” it said in a statement. “We are committed to determining the incident’s root cause and applying findings to future missions.”

Vance’s office did not immediately return a request for comment on Sunday.