Cpl. Patrick Tillman, killed in Afghanistan last month after spurning a $3.6 million football contract to join the special forces, was probably shot by his own comrades in the confusion of battle, the military said on Saturday.

　　An investigation of the April 22 death of Tillman, 27, an ex-safety for the National Football League's Arizona Cardinals, did not blame any individual.

　　Previous military statements had suggested Tillman, perhaps the best-known U.S. casualty of the Iraq and Afghan campaigns, had been killed by enemy fire.

　　"While there was no one specific finding of fault, the investigation results indicate that Cpl. Tillman died as a probable result of friendly fire while his unit was engaged in combat with enemy forces," the U.S. Central Command said in a statement.

　　The term "friendly fire" is used by the military to describe an accidental or mistaken attack on one's own forces or allies.

　　Tillman's elite Army Ranger platoon was ambushed by 10 to 12 fighters firing small arms and mortars while on patrol at about 7:30 p.m. near Khost, in southeastern Afghanistan, the Army Special Operations Command said in Fort Bragg, North Carolina.

　　The ambushers struck from "multiple locations over approximately one kilometer in very severe and constricted terrain with impaired light conditions," the Central Command said.

　　Tillman left his combat vehicle and, "in support of his unit, moved into position to suppress enemy fire," the command said.

　　The investigation's findings "in no way diminish the bravery and sacrifice displayed by Cpl. Tillman," the statement said.

　　'INHERENT DANGER OF CONFUSION'

　　"There is an inherent degree of confusion in any firefight, particularly when a unit is ambushed, and especially under difficult light and terrain conditions which produces an environment that increases the likelihood of fratricide," the military said.

　　Tillman turned down a three-year NFL contract to join the Rangers along with his brother, Kevin, eight months after the Sept. 11, 2001, attacks on the United States. He had played four seasons with the Cardinals. His Army annual salary was $18,000.

　　Both Tillmans took part in the U.S.-led invasion of Iraq before being deployed to Afghanistan to fight al Qaeda guerrillas and their allies in the ousted Taliban militia.

　　In April, the Army said Tillman had been promoted posthumously to corporal from specialist and it awarded him the Silver Star, its third highest decoration for combat valor.

　　At the time, it said Tillman's platoon had been split into sections during the fatal combat patrol. Describing Tillman as a team leader, the Army Special Operations command said on April 30 he had led his comrades up a hill to fire back at insurgents.

　　Fratricide is an age-old problem in war. U.S. military scholars say the percentage of deaths resulting from it has grown in line with technological advances that have boosted operational tempo on the battlefield.

　　In the 1991 Gulf War that drove Iraqi from Kuwait, 35 of 146 Americans who died in combat were killed by other Americans.

　　This compared with an average of about 15 percent in World War II, Korea and Vietnam, according to a 2001 article in National Review Online by Mackubin Owens, a professor of strategy and force planning at the U.S. Naval War College.