U.S. Border Patrol spokesman Doug Mosier said armed officers with Mexico's Secretaria de Seguridad Publica federal police were in the incursion, which took place in El Paso, near the Border Patrol's Ysleta station.
The Mexican government, Border Patrol and Texas Parks and Wildlife Department are investigating the incident. U.S. authorities responded to the incident.
A woman contacted the station early Thursday, saying her son, husband and friends were hunting on the Rio Grande levy on the U.S. side when men on the Mexico side fired shots, narrowly missing them. She said more men on the Mexico side drove up with automatic weapons and into to U.S. side. She said the armed men fired weapons and stole hunters' chairs and drove back into Mexico.
Mosier said Border Patrol agents and Texas Parks and Wildlife officers were sent to the area immediately.
"Upon approach, our agents observed those subjects (Mexican officers) who committed the incursion return back to Mexico," Mosier said.
Mosier said that at no point of the initial investigation were there any allegations of shots being fired at subjects on the U.S. side of the border, nor is there any information to suggest that any personal items were stolen from the U.S. side of the international boundary.
"We remain in constant and direct contact with our partners in the government of Mexico as the investigation unfolds."