YUMA, Ariz. -- A U.S. Border Patrol agent killed after being struck by a fleeing vehicle along the border in Imperial County has been identified as a 32-year-old husband and a father of two.

Agency spokesman Michael Bernacke says Senior Patrol Agent Luis Aguilar was trying to stop a suspected smuggler who had illegally entered the country from Mexico Saturday when he was hit by the vehicle.

The California Highway Patrol closed freeway ramps at Grey's Well Road, between Yuma and El Centro, but traffic on Interstate 8 itself was not affected.

The Yuma Daily Sun reported that the two vehicles, a Hummer that hit the agent and an accompanying Ford F-150 pickup truck, were being chased west on I-8 from a checkpoint near Yuma. As the cars exited the freeway at Grey's Well Road, Aguilar was struck.

The vehicles sped south through sand dunes towards Mexico. Interstate 8 is less than one mile north of Baja California at that location, and the two vehicles were last seen speeding towards Mexico federal Highway 2 east of Mexicali.

The sand dunes are a popular off-road vehicle playground, and the border fence in the area is frequently overrun by some of them.