The Army general who investigated the abuse of U.S.-held prisoners in Iraq today blamed a "failure of leadership" for the problem but said he found no evidence that the soldiers who committed the mistreatment were acting on orders from senior officers.

Maj. Gen. Antonio M. Taguba told the Senate Armed Services Committee that six or seven military police at the Abu Ghraib prison acted "on their own volition" in committing the abuses in collaboration with several low-level military intelligence interrogators, including civilian contractors, whom they considered competent authorities.

"At the end of the day, a few soldiers and civilians conspired to abuse and conduct egregious acts of violence against detainees and other civilians outside the bounds of international laws and the Geneva Convention," Taguba told the committee during three hours of testimony on the scandal that has riveted the nation for the past two weeks.

In a last-minute change, reportedly at the behest of the Pentagon, Taguba appeared jointly before the committee with two senior Defense Department officials: Stephen A. Cambone, the undersecretary for intelligence, and Air Force Lt. Gen. Lance L. Smith, the deputy commander of the U.S. Central Command.

Taguba, 53, the author of a 6,000-page report on the 800th Military Police Brigade, the unit with overall responsibility for Abu Ghraib, agreed with Cambone and Smith that the soldiers at the notorious prison west of Baghdad were not committing the abuses under orders from higher-ups. But Taguba expressed disagreement with Cambone over who had ultimate control over the prison and over the appropriateness of collaboration between military police and intelligence operatives to set the conditions for interrogating detainees.

Taguba, the deputy commanding general for support of the Coalition Forces Land Component Command in Kuwait, appeared before the Senate committee as part of its efforts to obtain a full accounting of the prisoner abuse and ensure that it does not happen again.

In an opening statement, Sen. Carl M. Levin (D-Mich.), ranking Democrat on the committee, said a hearing last week, in which Defense Secretary Donald H. Rumsfeld apologized for the abuse, "barely scratched the surface" of the issues before the panel, including the responsibility of senior officers for creating "an environment in which the abuses could occur."

Levin said, "The despicable actions described in General Taguba's report not only reek of abuse, they reek of an organized effort and methodical preparation for interrogation." He said the collars used on prisoners, the military dogs that intimidated and bit them and the cameras that photographed them in sexually compromising positions "did not suddenly appear out of thin air" and that the abuses "were not the spontaneous actions of lower-ranking enlisted personnel who lacked the proper supervision." Rather, Levin said, "These attempts to extract information from prisoners by abusive and degrading methods were clearly planned and suggested by others."

Asked by the committee chairman, Sen. John W. Warner (R-Va.), to explain "what went wrong," Taguba said: "Failure in leadership, sir, from the brigade commander on down, lack of discipline, no training whatsoever and no supervision."

Taguba said later, however, that his investigation did not uncover any evidence of "an overall military intelligence policy" that directed such abuses. A separate investigation into the actions of military intelligence operatives at Abu Ghraib is underway. Taguba said he believed the abuses resulted from military police guards' interactions with military intelligence personnel whom the guards perceived as "competent authorities" and who influenced the actions of the military police.

Responding to a question from Sen. Robert C. Byrd (D-W.Va.) on who "gave the order to soften up these prisoners," Taguba said, "We did not find any evidence of a policy or a direct order given to these soldiers to conduct what they did. I believe that they did it on their own volition. I believe that they collaborated with several [military intelligence] interrogators at the lower level," based on information obtained from interviews and written statements. "We didn't find any order, written or otherwise, that directed them to do what they did."

Taguba said that, for example, the digital cameras used to photograph some of the abuses were the "personal cameras" of the guards and that the pictures were not taken on any orders from higher-ups.

Lt. Gen. Smith said that "the photographing of prisoners, especially with private cameras, is against the rules."

Taguba, whose family emigrated to Hawaii from the Philippines when he was 11 years old, is the second highest-ranking Filipino American in the U.S. Army. His father, Tomas B. Taguba, served in the U.S. Army in the Philippines as a member of the Philippine Scouts during World War II and was captured by the Japanese at Bataan in 1942. He escaped from the infamous Bataan Death March, in which thousands of U.S. soldiers were brutalized by the Japanese and many died.

As Taguba entered the hearing room, he was greeted by several Filipino American veterans of World War II who were wearing their old uniforms and medals.

Senators of both parties praised Taguba's candor and attention to detail in compiling his report, the executive summary of which cited "numerous incidents of sadistic, blatant and wanton criminal abuses" of Iraqi detainees at the hands of their U.S. guards at Abu Ghraib, a vast 280-acre prison compound 20 miles west of Baghdad. Named the Baghdad Central Confinement Facility by the U.S. military, the prison complex has been used to hold as many as 7,000 Iraqis detained by U.S. forces. Under the regime of former president Saddam Hussein, it became infamous as a site of torture and executions.

Noting the prison's history under Hussein, one Republican senator, James Inhofe of Oklahoma, said he was "more outraged by the outrage" over the U.S. soldiers' abuse of the Iraqis than by the mistreatment itself. Many of the Iraqis now held there "probably have American blood on their hands," he said. "These prisoners wake up every morning thanking Allah that Saddam Hussein is not in charge of this prison," Inhofe said.

During the hearing, Cambone rejected Democratic senators' suggestions of a link between the abuses and a visit to Iraq in early September 2003 by a team from Guantanamo Bay, Cuba, headed by Maj. Gen. Geoffrey D. Miller, then commander of the detention facility there. The delegation recommended closer collaboration between the military police at Abu Ghraib and military intelligence, saying it was "essential that the guard force be actively engaged in setting the conditions for successful exploitation of internees."

Cambone denied that Miller's report was "tantamount to asking the military police to engage in abusive behavior."

But he and Taguba openly disagreed about the role of military intelligence at the prison. Cambone said military police have a duty to give interrogators information on the detainees. But Taguba cited Army regulations that delineate the responsibilities of guards and intelligence operatives so that the guards can run the prison smoothly and maintain the inmates' compliance.

The two also disagreed on a Nov. 19, 2003, order that turned over tactical control of Abu Ghraib to the 205th Military Intelligence Brigade under Col. Thomas M. Pappas. Cambone said that order did not mean that Pappas was in charge of the military police at the prison, but Taguba said it was clear that Pappas "was directed to be the [forward operating base] commander" for Abu Ghraib. Taguba said the order "created confusion and friction" between Pappas and the commander of the 800th Military Police Brigade, Army Reserve Brig. Gen. Janis L. Karpinski.

Sen. Hillary Rodham Clinton (D-N.Y.) asked Taguba to explain a disparity between his statements that Karpinski should be held accountable and her recent assertions that her military police committed the abuses on someone else's instructions. Taguba said he blamed Karpinski for "a lack of leadership on her part," notably with regard to overall training standards and the "command climate of her brigade."