At least two of the cases bear the hallmarks of the CIA's "extraordinary rendition" program _ stepped up after Sept. 11 _ in which the Bush administration has transferred dozens of suspects to third countries without court approval, subjecting them to possible torture.

In Italy, an Egyptian-born imam identified as Abu Omar had already drawn the attention of Italian anti-terrorism officials when he vanished off the streets of Milan two years ago, reportedly bundled into a van and flown back to Egypt from a joint U.S.-Italian air base.

"The prosecution is certain it was a kidnapping," prosecutor Armando Spataro told The Associated Press last week. He would not say who is suspected, citing judicial secrecy as the investigation is still under way.

Italian news reports say the CIA was believed to have played a role in the disappearance, and opposition politicians have demanded explanations from the government of Premier Silvio Berlusconi, a close ally of President Bush.

Citing conversations recorded by Italian anti-terrorism officials in a wiretap, the Corriere della Sera and La Repubblica newspapers reported that Omar, 42, called his wife and friends in Milan after his release last year. He recounted how he had been seized by Italian and American agents and taken to a secret prison in Egypt, where he was tortured with electric shocks. Italian officials say he is now living in Egypt, although Italian newspaper accounts suggested he was returned to custody in Egypt shortly after his release.

Asked about news reports alleging U.S. involvement, a U.S. Embassy spokesman in Rome, Ben Duffy, said, "We do not comment on intelligence matters."

Egyptian authorities have also refused to comment or discuss whether they cooperated.

Spataro, the prosecutor who usually handles terrorism cases involving Islamic militants, confirmed he visited Aviano, a joint U.S.-Italian base north of Venice, on Feb. 23 but declined to discuss any findings. He met with the Italian base commander, according to Duffy.

Omar was believed to have fought with jihadists in Afghanistan and Bosnia and Italian prosecutors were seeking evidence against him before his disappearance, according to a report in La Repubblica newspaper, which cited Italian intelligence officials.

Spataro said his disappearance damaged an ongoing operation, hurting the war on terror.

Opposition Sen. Tana de Zulueta asked the government whether Italy was involved in the disappearance but said she had not received a reply. The Interior Ministry, in charge of one of Italy's national police forces, referred questions to the prosecutor.

While Italian officials say Omar was abducted, the Swedish government is facing tough criticism at home by international human rights groups for having voluntarily handed over two Egyptian terror suspects to American agents.

Criticism over the case prompted Swedish police to draft new regulations on how to carry out deportation orders. The new rules say only Swedish officers can conduct body searches on Swedish territory and that Swedish officers must remain in charge.

"There is nothing that prevents police from asking for help (from another country), but it must be clear that the Swedish authorities are in charge of the situation," said National Police Board spokesman Hans Pont.

"We know that we will deport suspected terrorists in the future, but even with suspected terrorists you have to act correctly," Justice Minister Thomas Bodstrom told AP.

On Dec. 18, 2001, Swedish security police turned over Ahmed Agiza, 41, and Muhammed Alzery, 35, to U.S. agents at Stockholm's Bromma Airport. The Americans, wearing black masks, took the two into a small room and cut off their clothes with scissors, replacing them with prisoner uniforms, before placing them on a U.S.-registered Gulfstream jet, according to a report by Sweden's chief parliamentary ombudsman, a watchdog of state agencies.

The U.S. agents examined their mouths and ears, handcuffed them and fettered their ankles and placed hoods over their heads, the report said, calling the treatment "inhuman" and inconsistent with Swedish law.

Agiza was convicted by Egypt's Supreme Military Court on April 27, 2004, of belonging to and leading an outlawed group aiming to overthrow the government. He was sentenced to 25 years on the same charge in 1999 while he was in exile in Sweden. Alzery was released from an Egyptian prison last October, where he had been held on terrorism charges.

In Canada, Defense Minister Bill Graham testified at a hearing in Ottawa last month that he was upset Washington did not consult Ottawa's leaders before deporting a Canadian citizen to Syria for questioning on suspicion of terrorism. The case was handled by the Justice Department as an expulsion and not a rendition by intelligence agents.

Graham also expressed surprise that Canadian security officials apparently approved sending Maher Arar, to his native country for questioning about alleged ties to al-Qaida.

Graham told then-U.S. Ambassador Paul Cellucci it was "totally inappropriate" that Maher Arar was sent to Syria in October 2002 without first checking with Canadian officials.

"His response was that `We were totally entitled to do what we did,'" said Graham.

Arar, 35, holds dual Syrian-Canadian citizenship and was traveling on a Canadian passport when he was stopped in New York during a stopover while returning to Canada from Tunisia. He was held for 12 days before being sent to Syria on suspicion of being a member of al-Qaida, an allegation he denies.

Arar maintains that once imprisoned in Damascus, he was tortured into making false confessions of terrorist activity. Arar said he was held for more than a year in a dark, damp cell, then was released without ever being charged.

The U.S. Justice Department has insisted that it had information linking Arar to al-Qaida, that Syria promised he would be treated humanely and that shipping him there was "in the best interest of the security of the United States." Syria has denied he was tortured.

A U.S. counterterrorism official, speaking on the condition of anonymity because the process is classified, said rendition dates back several administrations and is used to get only the most serious terrorists off the streets, where there are only limited options.

In April the Dutch government denied the Netherlands had cooperated in the "extraordinary rendition" program, responding to questions from parliamentarians after the Washington Post reported U.S. intelligence officers had abducted terror suspects from European countries.

Germano Dottori, a political analyst at the Center for Strategic Studies in Rome, said the rendition operations are part of the American strategy of fighting terrorism through preventive action, but that if revealed can cause some damage to relationships between allied countries.

"No country appreciates intrusions into its sphere of national sovereignty and this is a very delicate sphere of sovereignty," he said.

Associated Press reporters Karl Ritter in Stockholm; Beth Duff-Brown in Toronto, Ariel David in Rome and Katherine Shrader in Washington contributed to this report.