A U.S. Border Patrol agent was assaulted while patrolling the border in Calexico Saturday.

The incident occurred at about 11:55 a.m. when the agent responded to the area of 1st and Dool Streets in Calexico where a man had been seen entering the U.S. illegally from Mexico through a breach in the old border wall. A second individual threw a softball-size rock through the border wall breach and it struck the Border Patrol agent in the face causing a serious laceration. The agent was transported to a local hospital for treatment and evaluation. The rock-thrower escaped. The man who illegally entered the U.S. was arrested.