A U.S. Border Patrol agent was hospitalized after being struck with a rock while patrolling the border on his all-terrain vehicle Saturday night, a federal official said.
The agent was traveling about 20 mph in southwest Otay Mesa when the grapefruit-size rock struck him in the chest and he crashed, supervisory Border Patrol Agent Michael Scappechio said.
The injured agent pushed the vehicle off and called for help. When other agents arrived, they spotted a group of people south of the border fence who they suspected were trying to enter the country illegally, Scappechio said.
The agents used tear gas to disperse the group and informed authorities in Mexico, who assisted in the process.
The injured agent was moved to a safe location and then taken to a hospital. He was held overnight and released Sunday with severe bruises to his chest.
He is now on administrative leave.
Border Patrol Agent Eduardo Olmos said no one was able to describe the person who threw the rock, but that investigators are working with authorities in Mexico to locate the assailant.
Olmos added that the close of 2017 had been particularly busy along the border. In the area where the assault occurred, agents over the weekend discovered seven places where the fence had been breached. More than 100 arrests were made, he said.
"This is an all-too-common occurrence." Chief Patrol Agent Rodney Scott said in a statement. "The safety and well-being of our agents remains our top priority, and we will work diligently with our law enforcement partners to bring the assailant to justice."