Two southeast Iowa high school students were charged Wednesday in a sexual abuse case.Ottumwa police say 17-year-old Brian Fugate admitted taking part in sex acts with a 13-year-old female while his friend, 17-year-old Benjamin Butler, videotaped the acts. Fugate is charged with third-degree sexual assault. Butler is charged with aiding and abetting in the sexual exploitation of a minor. The tapes reportedly were circulated at Ottumwa High School.