Mexican Military Cross Into U.S. - Hold Border Patrol Agent At Gun Point
The incident Sunday was the Mexican military's 43rd incursion across the U.S. border since October.
However, it was unusual because firearms were involved.
The Border Patrol and the Mexican government are investigating.
The incident occurred at 2 a.m. on the Tohono O'odham Indian Reservation about 50 miles southeast of Ajo.
The incident took place just north of the border in sight of the new border fence.
The soldiers held their weapons on the agent for several minutes until he identified himself in Spanish, whereupon they lowered their guns and walked back across a gap in the fence.