From the Arizona Daily Star:

U.S. Border Patrol agents were involved in two violent incidents with drug smugglers Wednesday and Thursday in downtown Nogales.

On Wednesday night at 10 p.m. east of the Dennis DeConcini port of entry, agents using a remote video surveillance system — a stand-alone 60-foot pole that holds four cameras — spotted three people carrying bundles, said Mike Scioli, Border Patrol Tucson Sector spokesman.
They lost sight of the trio as they made their way into a housing development butshortly after, spotted a sport utility vehicle leaving the area.

Agents tried to stop the black Ford Explorer as it headed south toward Mexico at high speeds. The vehicle came to a stop near the border and agents saw a a the driver get out and jump over the fence into Mexico, Scioli said.

Then, agents heard a yell followed by a volley of gunfire from Mexico. Agents took cover and were unable to identify the gunmen or if they shots were aimed at them, he said..
They called Mexican authorities who responded to the area but didn’t find the gunmen. Agents found three bundles of marijuana inside the sport utility vehicle weighing 158 pounds, Scioli said.

A few hours later, at 1 a.m. Thursday, camera operators spotted three men climbing the border fence at Short Street east of the Dennis Deconcini port of entry, he said. An agent driving an armored Border Patrol vehicle known as a “war wagon” responded to the area and was peppered by rocks from south of the line. He countered by using his pepper ball launcher to saturate the area, Scioli said.

The article goes on to relate the number of violent assaults on American Border Patrol agents since October 1st is 132. We don’t pay them enough.

This comes on the heels of an incident where Border Patrol had to fire at a truck barreling down on them to keep from being run down.