BUCKMAN SPRINGS, Calif. -- Four people were in custody Tuesday after a smuggling suspect tried to run over a U.S. Border Patrol agent at an East County freeway checkpoint, prompting the officer to open fire, authorities said.

The driver allegedly steered a vehicle carrying suspected illegal immigrants at the federal officer at the Buckman Springs-area citizenship verification station on westbound Interstate 8 about 4 p.m., according to the California Highway Patrol and USBP public affairs.

The agent suffered minor injuries, either when struck by the vehicle or while jumping out of the way, officials reported. The federal officer's gunfire caused no injuries, Border Patrol spokesman Jason Rodgers said.

It was unclear how many shots were fired, Rodgers said.

The suspected undocumented migrants were taken into custody a short time later.

The Highway Patrol shut down the westbound side of the freeway at Buckman Springs Road to allow for the investigation. Traffic was diverted onto Old Highway 80 and Sunrise Highway, then back onto I-8 in the Pine Valley area, according to the CHP.