Getting pelted with rocks -- it's an increasing trend for some local Border Patrol Agents.

Border Patrol Agents in Calexico, part of the El Centro sector, say they've seen an increasing number of rockings. Since the 2009 fiscal year began, agents say they've seen more than 100 rockings.

Agent Keith Croxton has experienced this first hand, and says it can be scary. First thing, his "adrenaline level spikes; you clear yourself and check your vehicle." After all, "anytime threat of health or well being there is a level of fear involved."

Most of the rockings within the El Centro sector occur in Calexico. In the past week, Calexico Agents have been attacked eight times.

One area prone to rockings -- first street along the border fence. There, people sit on top of the fence or in trees typically on the Mexico side of the border. They rock the agents below. Their goal can be anything from distracting to hurting agents.

A lot of rockings also happen in between the border fence and the truck lot fence by the New River. That's because illegal immigrants hide next to the fence, and smugglers don't want them caught by Border Patrol Agents.

To protect themselves, Agents use vehicles designed to be "rock proof." But usually only five to six of these vehicles are taken out at a time. If Agents are not in a "rock proof" vehicle, and they are attacked, they must rely on their self-deffense.

Croxton says they are "trained to get out of the way and use less-than-lethal weapons." This includes collapsible straight batons, OC spray and the FN-303 projectile launcher.

But even with these precautions, rockings can still put Agents in danger. Croxton explains, they can get hurt by broken glass from the windshield or windows. Injuries can be even worse if an Agent is rocked while on a bike or on foot.

Agents maintain an open line of communication with Mexican law enforcement agencies. Mexican authorities respond and try to apprehend suspects who are suspected of rocking agents.