An American citizen and a Canadian citizen were robbed and attacked by two armed suspected Mexican cartel terrorists while hiking in the Jacumba Wilderness north of the U.S.-Mexico border this week, U.S. Customs and Border Protection (CBP) announced on Thursday.

CBP says that California’s El Centro Sector Communications received a call from the Imperial County Sheriff’s Office 911 Dispatch reporting that a man had been shot in the El Centro Sector area of responsibility, which covers roughly 70 miles of the U.S.-Mexico border of Southern California in the Imperial Valley.

U.S. Border Patrol agents were dispatched to an area of the Jacumba Wilderness roughly 1,000 feet north of the border, where they found a group of hikers who reported part of their group had been attacked by armed individuals.

The group of hikers told Border Patrol agents that two of the hikers, one U.S. citizen and one Canadian citizen, were approached by two armed men who ordered the hikers to come toward them.

When the hikers refused, the armed men fired a volley of shots towards the hikers, striking the U.S. citizen in the leg. The two assailants then approached the injured hiker and the Canadian citizen, stealing their cell phones and backpacks.

Shortly after 12 p.m. on Wednesday, a Border Patrol tactical unit and search and rescue team found the injured victim and stabilized him. The agents created a protective perimeter and extracted the victim via helicopter to a hospital in San Diego for treatment.

CBP says the Border Patrol agents tracked the assailants back to the border where they returned to Mexico.

“The wounded hiker is an ‘I told you so moment’ highlighting the importance of adequate infrastructure the Border Patrol has been championing for years now,” said El Centro Sector Chief Gregory Bovino on Thursday.

“Suspected cartel terrorists, however, are fixing to learn this type of conduct will be an end game type of activity here in the Premier Sector,” Bovino said. “All threats, anywhere, or at any time throughout this sector will be addressed vigorously.”

Among a series of immigration-related executive order signed by President Donald Trump on Monday was an order designating cartels as foreign terrorist organizations.

“The Cartels functionally control, through a campaign of assassination, terror, rape, and brute force nearly all illegal traffic across the southern border of the United States,” President Trump’s order stated.

“In certain portions of Mexico, they function as quasi-governmental entities, controlling nearly all aspects of society,” it stated. “The Cartels’ activities threaten the safety of the American people, the security of the United States, and the stability of the international order in the Western Hemisphere.”