CORPUS CHRISTI -- A father is outraged after he said a man pulled to the side of the road and flashed his son Tuesday afternoon, making it the third incident involving a man flashing a child in the neighborhood in two years.

Ernesto Castellanos said his son, 11, was walking home from Culllen Middle School when a man driving a silver minivan pulled over and lifted his waist, exposing his genitals to the boy.

"He got scared. He just started running," he said. "When he started running he didn't want to go home because he was afraid he was going to turn around and follow him at the house."

There are 23 registered sex offenders within a mile radius of where it happened, but Castellanos said his son does not recognize any of them.

Castellanos said his son has had trouble sleeping since the incident.

Police are investigating the incident, but have nothing to go on except for the vehicle description.