A Border Patrol agent fired his gun at a suspect Monday afternoon.

The agent shot in self-defense, and does not know whether he hit the man, who fled across the Rio Grande to Mexico, leaving behind his Chevy Suburban packed with illegal immigrants, said Oscar Saldana, a spokesman for the agency.

The suspected coyote tried to run over the agent, Saldana said.

CBP is investigating the circumstances of the shooting in a rural area south of Donna, and have not yet determined whether the rounds hit their target, he said.

"The agent defended himself and there were no injuries to the agent," Saldana said.