Three U.S. Marines were found dead inside a parked car at a gas station in a coastal North Carolina community over the weekend, authorities said.

The Pender County Sheriff's Office said deputies were responding to a report of a missing person when they found the three Marines at about 9 a.m. Sunday at a Speedway convenience store on U.S. 17 in Hampstead, about 30 miles south of Marine Corps Base Camp Lejeune.

Their causes of death weren't immediately clear. The Pender County Sheriff's Office said it was investigating further.

"There does not appear to have ever been any threat to members of the community," the sheriff's office said.

The U.S. Marine Corps identified the three men as Marine Corps Lance Corporal Tanner J. Kaltenberg, 19, from Madison, Wisconsin; Marine Corps Lance Corporal Merax C. Dockery, 23, from Pottawatomie, Oklahoma; and Marine Corps Lance Corporal Ivan R. Garcia, 23, from Naples, Florida.

“My deepest sympathy and condolences are extended to (their) family, friends, and colleagues,” said Brig. Gen. Michael E. McWilliams, commanding general of 2nd Marine Logistics Group. “Our focus is providing the necessary resources and support to those impacted by their tragic loss as they navigate this extremely difficult time.”

The U.S. Marine Corps said in a release that the men were pronounced dead by a medical authority on Sunday. The 2nd Marine Logistics Group is assisting local authorities and the Naval Criminal Investigative Service.