The rate of suicide in the U.S. Army hit a 16-year high last year, with 99 soldiers killing themselves, a new military report says.

More than one out of four soldiers who committed suicide did so while serving in Iraq or Afghanistan, according to a report scheduled to be released Thursday. Iraq was the most common deployment location for U.S. soldiers who either attempted suicide or committed suicide.

The report, which The Associated Press obtained ahead of its public release, said the 99 confirmed suicides among active-duty soldiers compared to 88 in 2005 and was the highest raw number since the 102 suicides reported in 1991, the year of the Persian Gulf War, when there were more soldiers on active duty.

Investigations are still pending on two other deaths and if they are confirmed as suicides, the number for last year would be 101 instead of 99.

In a half-million-person Army, last year's suicide toll translates to a rate of 17.3 per 100,000, the highest in the past 16 years, officials report. The rate has fluctuated over those years, with the low being 9.1 per 100,000 in 2001.

Failed personal relationships, legal and financial problems and the stress of their jobs were factors motivating the soldiers to commit suicide, according to the report. It also found a significant relationship between suicide attempts and the number of days deployed in Iraq, Afghanistan or nearby countries where troops were participating in the war effort.

There was "limited evidence" to back the suspicion that repeated deployments are putting more people at risk for suicide, the report said. With the Army stretched thin by years of fighting the two wars, the Pentagon has had to extend normal tours of duty this year to 15 months from 12 and has sent some troops back to the wars several times.

The 99 suicides included 28 soldiers deployed to the Iraq and Afghan campaigns. About twice as many women serving in the wars committed suicide as did women not sent to war, the report said.

The Defense Manpower Data Center, which collects data for the Pentagon, said in late May that 107 suicides had been recorded in the Iraq campaign since its start in March of 2003.

Preliminary numbers for the first half of 2007 indicate the number of suicides could decline across the service but increase among troops serving in the wars, officials said.

The increases for 2006 came as Army officials worked to set up a number new programs and strengthen old ones for providing mental health care to a force strained by the longer-than-expected conflict in Iraq and the global counterterrorism war entering its sixth year.

In a flurry of studies in recent months, officials found that system that might have been adequate for a peacetime military has been overwhelmed by troops coming home from the wars.

Some troop surveys in Iraq have shown that 20 percent of Army soldiers have signs and symptoms of post-traumatic stress, which can cause flashbacks of traumatic combat experiences and other severe reactions. About 35 percent of soldiers are seeking some kind of mental health treatment a year after returning home under a program that screens returning troops for physical and mental health, officials have said.

The Army has sent medical teams annually to the battlefront in Iraq to survey troops, health care providers and chaplains about health, morale and other issues. It has revised training programs, bolstered suicide prevention, is adding some 25 percent more psychiatrists and other mental health professionals to its staff and is in the midst of an extensive program to teach all soldiers how to recognize mental health problems in themselves and their comrades — and encourage them to seek help.

The Army also has been working to stem the stigma associated with getting therapy for mental problems, after officials found that troops are avoiding counseling out of fear it could harm their careers.