WASHINGTON - Heightened attention to the crime of sexual assault in the U.S. military may be causing more people to come forward and report problems. Defense officials cite the increased awareness as a possible reason the number of reported sexual assaults rose more than 50 percent this year.

More than 5,000 reports of sexual assault were filed during the fiscal year that ended Sept. 30, compared with 3,374 in 2012, according to data obtained by the Associated Press. About 10 percent of the 2013 reports involved incidents that occurred before the victim got into the military, up from 4 percent only a year ago.

That increase, officials said, suggests that confidence in the system is growing and that victims are more willing to come forward. While cautious in their conclusions, officials said surveys, focus groups, and repeated meetings with service members throughout the year suggest the number of actual incidents - from unwanted sexual contact and harassment to violent assaults - remained largely steady.

A string of high-profile assaults and arrests triggered outrage in Congress and set off months of debate over how to change the military justice system. Military leaders launched a series of programs intended to beef up accountability and encourage victims to report crimes.

"Given the multiple data points, we assess that this is more reporting," said Col. Alan R. Metzler, deputy director of the Pentagon's sexual assault prevention and response office. He also noted that more victims are agreeing to make official complaints, rather than simply seeking medical care without filing formal accusations.

The military has long struggled to get victims to report sexual harassment and assault in a stern military culture that emphasizes rank, loyalty, and toughness. Too often, victims have complained that they were afraid to report assaults to ranking officers, or that their initial complaints were rebuffed or ignored.

As a result, the crime has been vastly underreported - a fact that became evident when officials announced this year that an anonymous survey had revealed that about 26,000 service members reported some type of unwanted sexual contact or sexual assault.

According to the latest numbers, the increase in reports across the services ranges from a low of about 45 percent for the Air Force to a high of 86 percent for the Marines, the smallest service. The Navy had an increase of 46 percent and the Army, by far the largest military service, had a 50 percent jump.

Jill Loftus, director of the Navy's sexual assault program, which also includes the Marine Corps, said the increase in reporting also suggests that more service members are starting to understand what types of behavior constitute harassment or assault.

Still, military leaders acknowledge a lot of work remains to be done. Metzler said the goal for this year is to continue efforts to increase reporting while also working more directly to reduce the survey number of 26,000 sexual harassment and assault victims.