Less than a week after a Department of Defense report found a sharp increase in sexual assaults at military academies, three Air Force Academy cadets have been charged with sexual assault.

Official documents say that Robert M. Evenson Jr. used his position as the Cadet Non-Commissioned Officer for Honor cases to obtain sexual favors from a female cadet, "and threatening to harm her military career if she did not comply."

A second count accuses him of "holding down Air Force Cadet [redacted] while masturbating over her and ejaculating on her stomach." He also allegedly raped a female cadet by "penetration of her vagina with his penis using power or strength or restraint to her person sufficient that she could not avoid or escape the sexual conduct."

Stephan H. Claxton is facing four charges of sexual assault, including striking and choking one or more cadets, placing a cadet's hand on his penis and attempting to engage in sexual contact with a cadet "by unbuttoning or unzipping her pants while she was substantially incapacitated."

Kyle A. Cressy's charge sheet says that he engaged in "penetration of the vagina of [redacted] with his hand or finger with an intent to arouse or gratify his own sexual desire." In another instance, he allegedly engaged in "penetration of the vagina of [redacted] with his penis, while the said [redacted] was substantially incapacitated."

In a statement Friday, Col. Tamra Rank, the Academy’s vice superintendent, said that the three cases were unrelated.

"The fact that the charges in all three cases are being preferred at this time is due to the near simultaneous completion of each individual investigation," Rank explained. "We expect the best from our cadets, and do not tolerate unacceptable behaviors."

Hearings next week will determine if the cases go to court-martial.

A Defense Department report released late last month determined that sexual assaults had increased by 60 percent in military academies during the 2010-2011 academic year.

Watch this video from CNN's Newsroom, uploaded Jan. 6, 2012.

Photo: Flickr/U.S. Air Force

(H/T: CNN)