Italy's defense minister was the target of hours of hostile questions and heckling in Parliament on Wednesday as outrage over the abuse of Iraqi prisoners by U.S. soldiers continued to shake the governments of European countries that have troops in Iraq.

Opposition members demanded that the official, Antonio Martino, disclose whether the Italian government, which has 2,700 troops in Iraq, knew about the mistreatment of Iraqis detained in U.S.- or British-run facilities before photographs of the abuse were made public. Martino answered no, but his response was interrupted by cries of "Shame!"

The growing scandal and the prospect of more damaging photographs and videotapes threaten to unravel the U.S.-led coalition in Iraq, which has already been shaken by continuing violence and Spain's decision to abruptly withdraw its 1,300 soldiers. Pressure has been particularly strong against the government of British Prime Minister Tony Blair.

In Hungary, which has 300 soldiers in Iraq, the scandal has eroded the broad political support behind the mission. The main opposition party, Fidesz, said it was time for Hungary to reconsider its position and has called for talks involving all political parties about the future of the mission.

The leader of Fidesz, Viktor Orban, a former prime minister who until recently supported the Iraq mission, this week called operations there "morally unsustainable." The government has agreed to hold talks with opposition parties about the issue.

The uproar in Hungary is "a direct response to the photographs," said Sebestyen L. Gorka, executive director of the Institute for Transnational Democracy and International Security, a research organization in Budapest. "It's on all the front pages here."

In Denmark, which has 500 soldiers in Iraq, Prime Minister Anders Fogh Rasmussen faced tough questions from lawmakers last week about whether Iraqis taken prisoner by Danish troops were mistreated after they were handed over to British forces, who run jails in the southern sector around the city of Basra.

"Denmark is responsible for the actions of Danish forces," Rasmussen responded. But in a concession, the government said its troops would make unannounced trips to the British facilities and inspect the treatment of prisoners.

In Poland, a key U.S. ally that commands a multinational sector in central Iraq, the prime minister-designate, Marek Belka, has insisted that "we're not going to bail out" of Iraq. Poland has 2,400 troops in Iraq, and Belka formerly worked as an economics adviser to the U.S.-led occupation authority in Baghdad.

Two Polish soldiers were killed last weekend in Iraq -- the country has lost a total of four -- and two Polish journalists died in an ambush, including Waldemar Milewicz, the country's best-known war correspondent.

"These activities in the prisons create huge difficulties for the American and multinational forces," retired Gen. Slawomir Petelicki, former commander of the Polish special forces, said in a telephone interview. But he said that in Poland, "the percentage of people supporting our participation is higher now, about 10 percent higher now, according to the polls. Because they shot and killed our soldiers and our journalists, more people are now supporting our participation."

In Italy, public opinion has been strongly against the war since it began. But Prime Minister Silvio Berlusconi has stuck with his policy of close cooperation with the Bush administration.

The prison scandal has also upset the Vatican and Catholic public opinion in Italy. The Vatican newspaper L'Osservatore Romano has been particularly stinging in its criticism.

In the tense and noisy parliamentary session Wednesday, Martino, the defense minister, fended off charges that the government had been aware of the accusations of abuse in Iraqi jails but had not acted or informed Parliament.

Martino said the government had been "in the dark" about the charges of torture and subsequent investigations until the scandal broke. He said the government was "surprised and indignant," and he called the opposition "anti-American and defeatist."

But the Italian chapter of Amnesty International has said that it informed the Italian government about abuses at two prisons, Abu Ghraib and Camp Cropper, according to La Repubblica newspaper. Martino said Amnesty had communicated directly with American authorities, but not with the Italians.

In a television interview Tuesday evening, the widow of one of the 19 Italians killed in an explosion at the Italian military headquarters in Nasiriyah last November said that her husband had seen evidence of violence and abuse against Iraqi prisoners.

Martino said an investigation was underway but added that the jails in question were managed by Iraqis. Italian military officials denied any reports of abuse in the jails under their watch, and the widow, in a subsequent radio interview, softened her earlier statements to clarify that her husband had not actually witnessed torture.

Special correspondent Sarah Delaney in Rome contributed to this report.

Defense Minister Antonio Martino said Italy had been "in the dark" about allegations of torture.