U.S. special forces freed four hostages in a raid Tuesday after staking out their captors' hideout for a day — the first military rescue of foreigners caught up in Iraq's wave of kidnappings.

But there was no word on the fate of a U.S. soldier held hostage and two other Americans missing since an attack on a fuel convoy nearly two months ago.

The raid ended the ordeal of a Pole kidnapped last week and three Italian security guards abducted in April whose co-worker was brutally slain. But Iraq's string of abductions showed no sign of abating.

Gunmen disclosed they had kidnapped seven Turkish citizens who they said were working with the Americans. They showed some of their captives to reporters and released videotape of the others.

More than 40 people from several countries have been abducted in Iraq since April. Many have been released. At least two have been killed by their captors.

About 20 are still being held, said Andrew White, an Anglican cleric acting as a negotiator.

But freeing the hostages is becoming a more difficult since some may have been sold by their captors to anti-U.S. militants, said White, the Mideast envoy of the Archbishop of Canterbury.

"Things are looking very bad for the hostages," he said. "My worry is that eventually these people will end up in the hands of groups such as Al Qaeda."

Meanwhile, Iraq saw a flare-up of bloodshed three weeks ahead of the handover of sovereignty on June 30. Car bombers blasted targets in two Iraqi cities Tuesday, killing 15 people — including a U.S. soldier — and wounding 50. Six European soldiers died when munitions they were transporting exploded south of Baghdad.

West of Baghdad, U.S. troops exchanged fire with insurgents in the town of Karma. An Iraqi doctor said at least two women died; the U.S. military said seven insurgents were killed.

In Tuesday's raid south of Baghdad that freed the hostages, U.S. troops detained a number of suspects.

Coalition troops uncovered the kidnappers' hideout Monday and observed it until the decision was made to move in, Italian Prime Minister Silvio Berlusconi (search) said.

There were only two guards in the hideout, and there was no bloodshed during the raid, he said.

Suspects "involved in the kidnapping" were detained, U.S. Lt. Gen. Ricardo Sanchez (search) told reporters in Baghdad. He said there were no reports of shots fired.

The four freed men were in good health, Sanchez said.

U.S. special forces carried out the raid, the commander of Polish forces in Iraq said.

The three Italians — Roberto Cupertino, Salvatore Stefio and Maurizio Agliani — were among the longest held hostages in Iraq. The three security guards were kidnapped April 12, along with their colleague Fabrizio Quattrocchi (search), who was killed by his captors soon afterward.

His slaying was recorded on a video that was not shown to the public, though Italian diplomats saw it. Quattrocchi became a hero in Italy when it emerged that in his last moments he defiantly told his captors, "Now I'll show you how an Italian dies."

The three were rescued along with Polish hostage Jerzy Kos, 64, who was abducted last week when seven men stormed his company's Baghdad office.

Over the past two months, kidnapping victims have run the gamut of the blue-collar workers toiling on behalf of the U.S.-led occupation of Iraq. They drive trucks, rebuild electrical plants, guard building sites.

American Nicholas Berg, a businessman, was beheaded by his captors, and his last moments later appeared on a videotape posted on an Al Qaeda-linked Web site. U.S. officials say Al Qaeda-linked militant Abu Musab al-Zarqawi may have been Berg's killer.

U.S. military officials have described the kidnappings as a tactic aimed at halting U.S.-led rebuilding work that was supposed to return jobs, electricity and a sense of normalcy to this battered country.

The CIA, Defense Intelligence Agency, FBI and military units are also involved in tracking kidnappers and their hostages in Iraq, a defense intelligence official in Washington said.

White, the Anglican negotiator, said tracking down who has the captives is complicated, especially as victims are handed over from kidnappers who are in it only for the money to more ideological anti-U.S. militants.

"The groups that kidnap them are selling them off to militant groups who sell them off again," White said.

He said that he has been in Iraq for 53 days, working with tribal leaders and sheiks to try to penetrate the complex network of hostage holders and to open negotiations with them.

It can be difficult to find reliable intermediaries, especially when the captives are from the United States or key allies in the U.S.-led coalition, he said.

The gunmen holding the seven new Turkish captives demanded private companies working with the U.S.-led occupation leave Iraq or face more attacks.

Turkish media later reported that two Turks were freed — though it was not clear if they were from the same group. Another Turk, an Egyptian and a Kuwaiti are also known to be held by kidnappers.

The Americans missing in Iraq were all part of a supply convoy that was attacked April 9 outside Baghdad.

Days later, Pfc. Keith M. Maupin of Batavia, Ohio, was shown in a video being held by masked gunmen.

The corpses of four contractors and one soldier from the convoy have been found. An American truck driver kidnapped in the attack, Thomas Hamill, escaped his captors last month.

Two truck drivers working for Halliburton subsidiary KBR — William Bradley of Chesterfield, N.H., and Timothy Bell of Mobile, Ala., remain missing.

"I'm not going to give up," Wilma Procter, Bradley's girlfriend, said. "There's no body found. You just don't vanish. That's the theory I've got to hold onto so I can continue with my life."