The Pentagon said it was pursuing five separate investigations Monday into allegations of abuse of Iraqi prisoners. One, launched in mid-April, delves into interrogation methods of U.S. military intelligence officers in Iraq (search).

President Bush urged Defense Secretary Donald H. Rumsfeld (search) to ensure that American soldiers found guilty of "shameful and appalling acts" be punished. A Pentagon spokesman said, "It's going to take some time to sort through exactly what the facts were."

A top aide to Bush, speaking on condition of anonymity, said the president wants a report on his desk quickly about the extent of prisoner abuse found by the Pentagon.

Members of Congress also pushed for swift action. The chairman of the Senate Armed Services Committee (search), Sen. John Warner (search), R-Va., summoned Pentagon officials to face his panel Tuesday.

"These allegations of mistreatment, if proven, represent an appalling and totally unacceptable breach of military conduct that could undermine much of the courageous work and sacrifice by our forces in the war on terror," Warner said.

Another Republican, Sen. Susan Collins of Maine, said she fears that photos depicting Iraqi prisoners in U.S. custody apparently being sexually humiliated and physically abused, which have been widely broadcast on TV in recent days, could incite more violence against American troops in Iraq.

Faced with a growing public-relations headache, Bush aides were trying to convince Arab counterparts the abuses were the exception, not the rule. The administration also is hoping that positive images of soldiers building schools and medical clinics will help counter the photos released last week of soldiers abusing Iraqi prisoners.

U.S.-financed Arabic-language television outlets in the Middle East could be used for airing constructive images, a senior administration official said. While the official insisted the administration does not control what is aired on the stations, the White House wants it to offer viewers a steady stream of favorable images, the official said, speaking on condition of anonymity.

In an effort to contain the mounting controversy, Larry Di Rita, Rumsfeld's chief spokesman, provided a timeline of U.S. military responses to the reported instances of abuse at the Abu Ghraib prison outside Baghdad. He said the abuse, alleged to have happened last fall, was reported to U.S. military commanders on Jan. 13 by a soldier in the 800th Military Police Brigade, commanded by Brig. Gen. Janis Karpinski of the Army Reserve.

A criminal investigation was launched the next day by the U.S. military command in Baghdad, headed by Lt. Gen. Ricardo Sanchez. On Jan. 19 Sanchez requested a high-level review of practices and procedures at detention and interrogation centers; on Jan. 31 the review was begun, under direction of Maj. Gen. Antonio M. Taguba. He finished it March 3.

In early February the Army inspector general began a review of U.S. detention facilities throughout Iraq and Afghanistan, at about the time the chief of the Army Reserve, Lt. Gen. James R. Helmly, began an assessment of training for his MPs and military intelligence personnel.

A fifth line of inquiry was started April 23. It is headed by Maj. Gen. George Fay, an assistant to the Army's deputy chief of staff for intelligence in the Pentagon, and it is focusing on military intelligence practices and procedures in Iraq, Di Rita said.

Di Rita said repeatedly that he could provide no information about the role of private contractors, who are alleged to have played a role in the abusive situation at the Abu Ghraib prison.

"I'll tell you right now, I have nothing to say about that. I just don't know anything about it," he said.

The criminal investigation was completed on March 15, Di Rita said, and on March 20 criminal charges were made against six military police. At least one of the six cases has been referred to military trial, and the others are in various stages of preliminary hearings, officials said.

Di Rita refused to release the names of the six. "The people have rights, and I believe we have privacy restrictions," he said. Later, he said: "I'm not in a position to put them on the record."

On Monday officials said seven officers, all military police, have been reprimanded in a form of noncriminal punishment. It was not clear whether others, including those in military intelligence, will face disciplinary action. The names of the seven have not been made public.

Di Rita said the findings of Taguba's report are classified and cannot be publicly released, although they have been reported in detail in the news media, initially by The New Yorker magazine.

Rumsfeld has not read or been briefed on the central findings of the Taguba investigation, Di Rita said, although he has kept abreast of the allegations that Iraqi prisoners have been mistreated.

Gen. Richard Myers, chairman of the Joint Chiefs of Staff, said Sunday that he too had not read the Taguba report.

Rumsfeld has had no public comment on the controversy since it began with the broadcast over the CBS News program "60 Minutes II" of photographs taken by U.S. military guards inside the Abu Ghraib prison last fall. Di Rita said Rumsfeld had not seen the photos before they were broadcast.

Asked why Rumsfeld had not demanded to see the Taguba report, or at least be briefed on its central findings, considering the international furor it probably would trigger, Di Rita said Rumsfeld's main interest was to ensure that all aspects of the matter be thoroughly investigated. He said it was not necessarily important at this point that Rumsfeld see the findings.

"There are criminal and administrative procedures going on in Iraq and Afghanistan and all around the world every single day" involving members of the U.S. military, Di Rita said. He said he realizes that those involving prisoner abuse are particularly egregious.

"His concern is that we can have confidence in the military justice system, which he does," Di Rita said. Because he is in the chain of command, he is restricted in what he can say and do about specific cases, the spokesman said.

The CIA, which is involved in some aspects of Iraqi prisoner interrogations, also is investigating, agency officials said.