¶ WASHINGTON — The Department of Defense released an annual report on Tuesday showing an 11 percent increase in reports of sexual assault in the military over the past year, including a 16 percent increase in reported assaults occurring in combat areas, principally Iraq and Afghanistan.

¶ The report said there were 3,230 reports of sexual assault filed involving service members as either victims or assailants in the fiscal year that ended in September. The Pentagon attributed the rise largely to an upward trend in the reporting of incidents, and said the jump did “not necessarily” reflect an increase in the number of incidents.

¶ The Pentagon offered no evidence that reporting rather than sexual assault itself was on the rise in the military, and there have been reports in recent years suggesting that the strains between men and women in close quarters in war zones have exacerbated the problem.

¶ But it is also true that since 2004 the Defense Department has radically changed the way it handles sexual abuse in the military, including encouraging victims to come forward, expanding access to treatment and toughening standards for prosecution.

¶ From 2007 to 2008, there was an 8 percent increase in reported assaults, with an 11 percent increase in combat areas. The Defense Department said that for the purposes of the 2009 report, “combat areas” included Saudi Arabia, Pakistan, Yemen and other countries in the Middle East and Central Asia where military men and women are serving.

¶ “One sexual assault is too many,” Kaye Whitley, the director of the Pentagon’s sexual assault prevention and response office, said in a telephone interview.

¶ The 2009 report, like previous reports, included sexual assaults by civilians on service members and by service members on civilians. But Ms. Whitley said a majority, 53 percent, were assaults by service members on other service members.

¶ Of all the assaults, Ms. Whitley said, a vast majority, 87 percent, were male on female, while 7 percent were male on male. The typical case, she said, was an assault by an 18- to 25-year-old junior enlisted male service member on a woman, with alcohol involved.

¶ In the report, sexual assault was defined as rape, sodomy and other unwanted sexual contact, including touching of private body parts. It did not include sexual harassment, which is handled by another office in the military.

¶ Ms. Whitley said that most sexual assault in the military went unreported, as it did in the general population, and that she did not believe that there was more sexual assault in the military than in the population at large. “We are recruiting from the society we serve,” she said.

¶ The report said that sexual assault was devastating to individual service members because it “destroys the human spirit,” but that it also took a serious toll on the military. “Sexual assault reverberates throughout a unit and beyond,” it said.