A steady stream of shocked Italians viewed the body of an Italian intelligence officer lying in state two days after American troops in Iraq shot and killed him, while the journalist whose life he saved said she had promised his widow she would find out why they were attacked.

Giuliana Sgrena (search), who was abducted Feb. 4 in Baghdad, spoke from a Rome (search) hospital where she was recuperating Sunday from a shrapnel wound to the shoulder. The intelligence officer, Nicola Calipari, was killed when U.S. troops at a checkpoint fired at their vehicle Friday as they headed to the airport shortly after her release.

Sgrena said Calipari died shielding her, and that it was possible they were targeted deliberately because the United States opposes Italy's policy of negotiating with kidnappers.

However, she has offered no evidence to support her claim, and in an interview published in Monday's edition of the daily Corriere della Sera (search), she said she doesn't know what led to the attack.

"I believe, but it's only a hypothesis, that the happy ending to the negotiations must have been irksome," she said. "The Americans are against this type of operation. For them, war is war, human life doesn't count for much."

Sgrena has rejected the U.S. military's account of the shooting, claiming instead that American soldiers gave no warning before they opened fire.

The White House said it was a "horrific accident" and promised a full investigation.

Sgrena, meanwhile, told private TG5 TV that she had spoken with Calipari's wife.

"The only thing that I promised and I want to guarantee to her is that we must know the truth, because such exceptional people cannot die for no reason," Sgrena said. "If someone is responsible, we need to know."

The shooting has fueled anti-American sentiment in Italy, where a majority of people opposed the war in Iraq and Premier Silvio Berlusconi's (search) decision to send 3,000 troops after Saddam Hussein's ouster.

One Italian Cabinet member urged Sgrena to show more caution in her remarks.

"I understand the emotion of these hours, but those who have been under stress in the past few weeks should pull themselves together and avoid saying nonsense," Communications Minister Maurizio Gasparri was quoted as saying by the ANSA news agency.

Gasparri said the shooting would not affect Italian support for efforts to secure postwar Iraq.

Neither Italian nor U.S. officials gave details about how authorities won Sgrena's release after a month in captivity. But Agriculture Minister Giovanni Alemanno was quoted as saying it was "very probable" a ransom was paid. U.S. officials have cautioned against ransoms, saying they encourage further kidnappings.

In an interview, without backing up her claim, Sgrena said it was possible she was targeted deliberately. The journalist, who works for the communist newspaper Il Manifesto — a fierce opponent of the war and a frequent critic of U.S. policy — said she knew nothing about a ransom, and offered no details on the talks.

"The fact that the Americans don't want negotiations to free the hostages is known," she told Sky TG24 television by telephone, her voice hoarse and shaky. "The fact that they do everything to prevent the adoption of this practice to save the lives of people held hostage, everybody knows that. So I don't see why I should rule out that I could have been the target."

In an article Sunday, Sgrena said her captors warned her shortly before her release to beware of the Americans. She later told Italian state TV RAI that "when they let me go, it was a difficult moment for me because they told me, `The Americans don't want you to return alive to Italy."' Sgrena didn't elaborate, and it wasn't clear if "they" referred to her captors.

Her editor, Gabriele Polo, said Italian officials told him 300 to 400 rounds were fired at the car. Italian military officials said two other intelligence agents were wounded in the shooting; U.S. officials said it was only one.

White House counselor Dan Bartlett said it was crucial that the facts be determined before judgments were made about the shooting

Speaking Sunday on CNN's "Late Edition," he called the shooting "a horrific accident" and pledged a full investigation.

"As you know, in a situation where there is a live combat zone, particularly this road to the airport has been a notorious area for car bombs," Bartlett said. "People are making split-second decisions, and it's critically important that we get the facts before we make judgments."

Calipari's body was returned to Italy late Saturday, and an autopsy was performed Sunday. ANSA quoted doctors as saying Calipari was struck in the temple by a single round and died instantly.

The body lay in state at Rome's Vittoriano monument and a state funeral was planned for Monday. At least 10,000 people paid their respects Saturday, and the chamber containing his coffin remained open early Sunday as people kept coming.

Calipari was to be awarded the gold medal of valor for his heroism.

Italian military officials said two other agents were wounded, but U.S. officials said it was only one.