"During the assault at least one agent discharged his firearm," he said. "The agent is currently on administrative leave. A thorough, multi-agency investigation is currently ongoing."
Mexicans angry as U.S. Border Patrol kills teen →
Preliminary reports on the incident indicated that U.S. officers on bicycle patrol "were assaulted with rocks by an unknown number of people," Border Patrol Special Operations Supervisor Ramiro Cordero said Tuesday.