RENEE MONTAGNE, host:

Tensions over the war in Iraq and the US treatment of detainees erupted on the Senate floor last night. In an unusual debate that was both unexpected and highly personal, senior Republicans accused a Democrat of denigrating American troops but soon found themselves on the defensive. More from NPR's David Welna.

DAVID WELNA reporting:

It all began Tuesday when Democratic Whip Dick Durbin of Illinois declared on the Senate floor he had something to read, though he did so, he said, with some hesitation. It was a report submitted to a Pentagon investigator and it described detainees at the US prison in Guantanamo Bay, Cuba, being chained, hand and foot, to the floor in their own excrement and subjected to extreme temperatures. Here's Durbin.

Senator RICHARD DURBIN (Democrat, Illinois): If I read this to you and I did not tell you that it was an FBI agent describing what Americans have done to prisoners in their control, you would most certainly believe this must have been done by Nazis or Soviets in their gulags or some mad regime, Pol Pot or others, that had no concern for human beings. Sadly, that is not the case. This was the action of Americans in the treatment of their prisoners.

WELNA: Last night, shortly after White House spokesman Scott McClellan denounced Durbin's remarks as, quote, "simply reprehensible," John Warner, the Virginia Republican who chairs the Armed Services Committee, expressed his own dismay on the Senate floor.

Senator JOHN WARNER (Republican, Virginia): And I just was astonished, and I just did not want to let, this day, the sun go down without conveying to the Senate my own historical perspective and the danger that loose comments such as that, comparisons which have no basis in fact or history, could do harm to the men and women serving wherever they are in the world today in this war on terrorism.

WELNA: Joining Warner was Republican Whip Mitch McConnell.

Senator MITCH McCONNELL (Republican, Kentucky): I just want to thank my friend from Virginia for, you know, clearing up any notion anyone might have that anything the United States is involved in in incarcerating prisoners would be in any way related to experiences such as those carried out by the Nazis or by the Russians during the Stalin period.

WELNA: Warner had a suggestion.

Sen. WARNER: I really feel so strongly, I say to the distinguished leader of our party, that I feel apologies are in order to the men and women of the armed forces.

WELNA: Democrat Durbin then showed up on the Senate floor to defend himself. Far from apologizing, he called his colleagues' criticism totally unfair.

Sen. DURBIN: I was attributing this form of interrogation to repressive regimes such as those that I noted. And I honestly believe the senator from Virginia, whom I respect very, very much, would have to say, if this indeed occurred, it does not represent American values. It doesn't represent what our country stands for. It is not the sort of conduct we would ever condone. I would hope the senator from Virginia would agree with that. That was the point I was making.

WELNA: Warner said Durbin had concluded too hastily prisoners were mistreated at Guantanamo.

Sen. WARNER: My understanding, it is currently under investigation and being carefully scrutinized in the context of another series of documents. So until the administration has had the opportunity to complete the investigation and make their own assessment of the allegations, it seems to me premature to render judgment.

Sen. DURBIN: What I described was the interrogation techniques approved by this administration in the extreme. There was nothing in this description here from the agent of the Federal Bureau of Investigation which was different than the interrogation rules of engagement which had already been spelled out.

WELNA: Democratic leader Harry Reid then rose in the Senate to defend his colleague.

Senator HARRY REID (Democrat, Nevada): This is all a distraction by the White House. Why? Because, Madame President, this country is in trouble for lots of reasons, only one of which is Iraq.

WELNA: All signs indicate this debate, having burst out at last, is bound to continue.

David Welna, NPR News.

MONTAGNE: This is MORNING EDITION from NPR News. Transcript provided by NPR, Copyright NPR.