WASHINGTON, May 26 - The American military commander at Guantánamo Bay, Cuba, said today that investigators had found "no credible evidence" that a Koran had ever been flushed down a toilet there to unsettle detainees, and no serious incidents of intentional mishandling of the Muslim holy book by Americans.
The commander, Brig. Gen. Jay W. Hood of the Army, said 13 possible incidents had been investigated in which the book might have been mishandled: 10 by guards and 3 by interrogators. Of the 13, only 5 embody "what could be broadly defined as mishandling of a Koran," the general said, but declined to provide details.
In several other incidents, he said, guards had accidentally touched the book or touched it "within the scope of their duties." And in two other incidents, both involving interrogations, there was possible inadvertent mishandling, General Hood said.
"We've also identified 15 incidents where detainees mishandled or inappropriately treated the Koran, one of which was the specific example of a detainee who ripped pages out of their own Koran," the general said.
The general's Pentagon briefing was part of an attempt to quell bitter feelings in the Muslim world sparked by reports of mistreatment of the holy book. General Hood said he was confident that the guard force's procedures for handling the book were adequate, but he also said that they were continually reviewed.
As for the detainees, he said, "this is not a benign group of people." He said the prisoners constituted "a clear and present danger" to the United States, and that interrogations continued to provide valuable intelligence.
On Wednesday, newly released documents showed that detainees at Guantánamo had complained repeatedly to F.B.I. agents about disrespectful handling of the Koran by military personnel and, in one case in 2002, said they had flushed a Koran down a toilet.
The prisoners' accounts were described by the agents in detailed summaries of interrogations at Guantánamo in 2002 and 2003. The documents were among more than 300 pages turned over by the F.B.I. to the American Civil Liberties Union in recent days and publicly disclosed on Wednesday.
Unlike F.B.I. documents previously disclosed in a lawsuit brought by the civil liberties union, in which agents reported that they had witnessed harsh and possibly illegal interrogation techniques, the new documents do not say the F.B.I. agents witnessed the episodes themselves. Rather, they are accounts of unsubstantiated accusations made by the prisoners during interrogation.
On Wednesday, the Pentagon dismissed the reports as containing no new evidence that abuses of the Koran had actually occurred and said that on May 14 military investigators had interviewed the prisoner who mentioned the toilet episode to the F.B.I. and that he was not able to substantiate the charge.
The accusation that soldiers had put a Koran in a toilet, which has been made by former and current inmates over the past two years, stirred violence this month that killed at least 17 people in Muslim countries after Newsweek magazine reported that a military investigation was expected to confirm that the incident had in fact occurred.
Newsweek retracted the report last week, saying it had relied on an American government official who had incomplete knowledge of the situation.
None of the documents released on Wednesday indicated any such confirmation that the incident took place.
One document is an Aug. 1, 2002, memorandum from an agent whose name is deleted that recounts a pair of interviews the previous month with a prisoner whose name is also deleted.
The prisoner said that "the guards in the detention facility do not treat him well," the agent wrote. "Their behavior is bad. About five months ago, the guards beat the detainees. They flushed a Koran in the toilet. The guards dance around when the detainees are trying to pray. The guards still do these things." The document does not indicate whether the agent believed the account.
The documents include several other accounts of detainees' complaints about disrespectful handling of the Koran, but none describe its being flushed in a toilet.
The deputy Pentagon spokesman, Bryan Whitman, said on Wednesday that the newly released document, a summary of an interrogation, "does not include any new allegations, nor does it include any new sources for previous allegations." Mr. Whitman said the source of the accusation "is an enemy combatant."
Since the Newsweek article was published, the Pentagon has been reviewing records, but "we still have found no credible allegations that a Koran was flushed down a toilet at Guantánamo," Mr. Whitman said on Wednesday, an assertion echoed today by General Hood.
Until the new batch of documents was released, no previously released F.B.I. documents were known to have mentioned abuse of the Koran of the type Newsweek reported.
Earlier complaints came in statements of inmates after they were released from custody or, more recently, in statements of current inmates to their lawyers.
Another memo released on Wednesday, dated March 18, 2003, is an account by an agent whose name is deleted who writes that another detainee told him of purposely disrespectful handling of the Koran. The detainee acknowledged, according to the memo, that he did not witness any of the incidents he had discussed.
The agent reports that the detainee said the use of the Koran as a tool in interrogation had been a mistake. "Interrogators who had taken the Koran from individual detainees as a reprisal or incentive to cooperate had failed," the detainee said, adding that the only result would be "the damage caused to the reputation of the United States once what had occurred was released to the world."
Jameel Jaffer, a senior lawyer at the American Civil Liberties Union, who is coordinating the review of documents obtained in the group's civil suit against the military, said the documents were part of more than 300 new pages received last Thursday from the Federal Bureau of Investigation. He said staff members spent days reviewing the documents.
Ken Weine, a spokesman for Newsweek, said the magazine would have no comment on the disclosures.
The disclosures on Wednesday did not support the specific assertions in the original Newsweek item that military investigators concluded that a Koran had been flushed down a toilet. They do, however, reinforce the contentions of human rights advocates and lawyers for detainees that accusations of purposeful mishandling of the Koran were common.
A former interrogator told The New York Times in a recent interview that friction over handling of the Koran began with guards' regular searches of the cells. "Some of it was just ignorance," the former interrogator said, insisting on anonymity because soldiers are barred from discussing camp operations. "They didn't realize you shouldn't handle the book roughly."
Though complaints about the handling of the Koran were routine, the former interrogator said, the situation eventually escalated. "It was two things that brought the desecration issue to a higher level," the former interrogator said. "The rumor spread among detainees that a Koran had been flushed down a toilet and that some interrogators brought Korans to the interrogation sessions and stood on them, kicked them around." The former interrogator had not witnessed those occurrences.
Erik Saar, co-author of "Inside the Wire" (Penguin Press, 2005) and an Arabic language translator in 2003 in Guantánamo said in a recent interview that "the detainees actually liked to complain about how the Koran was handled because they viewed it as a cause to rally around" and one that would get the attention of the camp's authorities.
Mr. Jaffer of the A.C.L.U. said the errors in the Newsweek report had been improperly used to discredit other information about abusive practices at Guantánamo "that were not based on anonymous sources, but government documents, reports written by F.B.I. agents."
The new documents and 30,000 pages previously released were disclosed as part of a suit brought by the A.C.L.U. and other groups trying to learn whether and what kinds of coercive tactics were used at Guantánamo.
The earlier release of reports in which bureau agents recounted witnessing harsh interrogations resulted in an investigation by an Air Force general of interrogation practices. That report, which was completed at the end of March, has not yet been released by the Pentagon.