Violent sex crimes committed by active U.S. Army soldiers have almost doubled over the past five years, due in part to the trauma of war, Reuters said citing an Army report.

Reported violent sex crimes increased by 90 percent over the five-year period from 2006 to 2011. There were 2,811 violent felonies in 2011, nearly half of which were violent felony sex crimes. Most were committed in the United States.

One violent sex crime was committed by a soldier every six hours and 40 minutes in 2011, the Army said, serving as the main driver for an overall increase in violent felony crimes.

Higher rates of violent sex crimes are "likely outcomes" of intentional misconduct, lax discipline, post-combat adrenaline, high levels of stress and behavioral health issues, the report said.

Violent sex crimes committed by U.S. Army troops increased at a rate that consistently outpaced the national trend, a gap that is expected to continue to grow, the Army said.

The top five violent felony offenses committed by soldiers in 2011 were aggravated assault, rape, aggravated sexual assault, forcible sodomy and child pornography.

Soldiers suffering from issues such as Post-Traumatic Stress Disorder (PTSD), traumatic brain injury, and depression have been shown to have higher incidences of partner abuse, according to the report.

As the largest branch of the U.S. armed forces, the Army has done the bulk of the fighting in Iraq and Afghanistan, including years of extended duty and repeated deployments. The rate of suicides among Army soldiers was steady in 2011 after years of rising, the report said.