The U.S. Border Patrol said a group of its agents came under fire from the Mexican side of the Rio Grande in Starr County on Friday.
Officials said field training units were showing agents around just south of the levee in Frontron when they came under fire around 4 p.m. Friday.
The group conducting foot patrols when they heard noise.
Agents said they started receiving gunfire from the Mexican side of the Rio Grande River.
Officials told Action 4 News that at least 40 to 60 rounds of ammunition were fired at the agents.
The Border Patrol agents retreated and did not fire back.
No injuries were reported.