Washington ? In a survey of U.S. troops in combat in Iraq, less than half of Marines and a little more than half of Army soldiers said they would report a member of their unit for killing or wounding an innocent civilian.

More than 40 percent support the idea of torture in some cases, and 10 percent reported personally abusing Iraqi civilians, the Pentagon said Friday in what it called its first ethics study of troops at the war front. Units exposed to the most combat were chosen for the study.

“It is disappointing,” said analyst John Pike of the Globalsecurity.org think tank. “But anybody who is surprised by it doesn’t understand war. … This is about combat stress.”

The military has seen a number of high-profile incidents of alleged abuse in the wars in Iraq and Afghanistan, including the killings of 24 civilians by Marines in Haditha, the rape and killing of a 14-year-old girl and the slaying of her family in Iraq, and the sexual humiliation of detainees at Abu Ghraib prison.

The overall study was the fourth in a series done by a mental health advisory team since 2003 aimed at assessing the well-being of forces serving in Iraq.

The study team also found that long and repeated deployments were increasing troop mental health problems.

But Maj. Gen. Gale Pollock, the Army’s acting surgeon general, said the team’s “most critical” findings were on ethics.

“They looked under every rock, and what they found was not always easy to look at,” said Ward Casscells, assistant secretary of defense for health.

Findings included:

¢ Sixty-two percent of soldiers and 66 percent of Marines said that they knew someone seriously injured or killed, or that a member of their team had become a casualty.

¢ The 2006 adjusted rate of suicides per 100,000 soldiers was 17.3 soldiers, lower than the 19.9 rate reported in 2005.

¢ Only 47 percent of the soldiers and 38 percent of Marines said noncombatants should be treated with dignity and respect.

¢ About a third of troops said they had insulted or cursed at civilians in their presence.

¢ About 10 percent of soldiers and Marines reported mistreating civilians or damaging property when it was not necessary. Mistreatment includes hitting or kicking a civilian.

¢ Forty-four percent of Marines and 41 percent of soldiers said torture should be allowed to save the life of a soldier or Marine.

¢ Thirty-nine percent of Marines and 36 percent of soldiers said torture should be allowed to gather important information from insurgents.