Updated

As a British man being held hostage in Iraq (search) begged for his life to be saved, a pair of separate statements were released claiming the execution of two female Italian hostages.

On Wednesday, an Internet statement purportedly by a group which claimed to have kidnapped two Italian aid workers in Baghdad said it had killed the women. On Thursday, a second militant group claimed in a Web posting that the two Italian women had been killed and that a video of the slayings would be released. Neither claim could be immediately verified.

The deaths of the pair, who were working for "Un Ponte Per ..." ("A Bridge to ..."), would be the first murders of women hostages in the country since the war began.

Simona Pari (search) and Simona Torretta (search), both 29, were seized from their Baghdad offices by armed militants on Sept. 7. They worked for and were involved in school and water projects in Iraq.

The first claim they were killed was unusual because it appeared on a Web site not regularly used by Iraqi militants to relay their statements. A source close to Italian Premier Silvio Berlusconi said the government suspected the claim might not be credible. '

"Italian intelligence services ... believe these claims to be completely unreliable," Enzo Bianco, the head of the parliament commission overseeing secret services, told Italian news agencies. "Un Ponte Per..." did not have any comment.

The first statement came Wednesday from a group calling itself the Islamic Jihad Organization Iraq, which said it killed the two women because Italy had ignored demand to withdraw troops from Iraq.

A new statement Thursday was signed by a group named the Supporters of al-Zawahri, saying the heads of the two women — "criminal agents of Italian intelligence" — were "chopped off by knife without pity or mercy."

It said it killed the women because its demands — the departure of Italian forces, the release of female prisoners in Iraq, and the help in gaining freedom for female Chechen prisoners and all Arab detainees in Israel — were not met.

Plea for Mercy

On Wednesday, the British captive, Kenneth Bigley (search), was seen in a video appealing to Prime Minister Tony Blair (search) to intervene. "I think this is possibly my last chance," he said. "I don't want to die."

Bigley's brother, Paul, accused the United States of sabotaging efforts to save his brother's life. He told the British Broadcasting Corp. on Thursday that his hopes were raised when Iraqi ministers said one of the female prisoners would be freed. But soon afterward, a U.S. Embassy spokesman ruled out any immediate release.

"That was a shadow of light in a big, long, dark, damp, filthy, cold tunnel. Now this has been sabotaged," he said.

Bigley's 86-year-old mother pleaded for her son's freedom.

"Please show mercy to my Ken and send him home to me alive," she said, holding back tears as she sat with two other sons. "His family need him. I need him."

Bigley's wife also appealed to the kidnappers to release her husband. Sombat Bigley, a Thai woman, said she had seen the video with Bigley's plea for help.

"We have been married for seven years and I love him very much ... I desperately want to be reunited with my husband," she said, reading a Thai-language statement in front of news television cameras in Bangkok.

In Wednesday's video, Bigley said Blair was the only man who could keep his kidnappers from killing him.

"Mr. Blair, I am nothing to you. Here's just one person living in the United Kingdom, that's all, with a family like you, like your family, your children, your boys, your wife," the speaker said in the grainy video.

"Please, you can help. I know you can," he said, addressing the British prime minister.

He wore an orange jumpsuit, the kind that kidnappers put on their hostages before killing them and like those issued to prisoners held by American forces at the U.S. military prison at Guantanamo Bay, Cuba.

Bigley sobbed in the middle of his message and wiped his forehead. A banner of the Tawhid and Jihad militant group hung on the wall behind him.

Bigley was being held by a militant group led by Jordanian-born terror mastermind Abu Musab al-Zarqawi. The group has already beheaded Americans Eugene Armstrong (search) and Jack Hensley (search), whom it abducted along with Bigley from the Westerners' Baghdad home last week. The militants demanded the release of all female prisoners in Iraq.

Iraqi Prime Minister Ayad Allawi (search) expressed his condolences for the Americans' deaths during a visit to Washington on Thursday. "Yet as we mourn these losses, we must not forget the progress we are making or what is at stake in Iraq. We are fighting for peace and democracy," he told U.S. lawmakers.

Secretary of State Colin Powell told The New York Post on Wednesday that Bigley's plea "will be a very emotional issue in Britain" and could "complicate" Blair's political situation.

But he said the terrorists demands could not be met, even though some of the women may be released later. "We can't have them connected," he said.

On Wednesday, the group posted a video of Hensley's killing on the Internet, as it had two days earlier of Armstrong's beheading.

Earlier, Britain's Foreign Secretary Jack Straw appeared to hold out little hope for saving Bigley.

"We continue to do everything we can to secure Kenneth Bigley's safe release, but it would be idle to pretend that there's a great deal of hope," Straw told reporters in New York.

Tawhid and Jihad — Arabic for "Monotheism and Holy War" — has claimed responsibility for the slaying of at least seven hostages, including American Nicholas Berg. More than 130 foreigners have been kidnapped in Iraq, and at least 26 of them have been killed.

Violence Rages On

A U.S. Marine assigned to the 1st Marine Expeditionary Force was killed on Wednesday while conducting security operations in Anbar province, the military said Thursday. Three U.S. soldiers were also killed in separate incidents in Iraq on Wednesday, and fighting wounded more than 100 people.

Homicide attackers struck key diplomatic and commercial centers of the capital, and American tanks and troops searching for weapons stormed into the slum of Sadr City, a stronghold of Shiite militants — only to come under a barrage of mortar and automatic weapons fire. The violence underscored the inability of U.S. and Iraqi forces to bring security to even the most vital areas of the capital.

In Sadr City on Thursday, U.S. warplanes and helicopters fired on insurgents, killing at least one person and injuring 12, many of them children, hospital officials said Thursday. Militia fighters returned fire with machine guns and residents said loud explosions could be heard for hours.

An American Bradley fighting vehicle was hit by a rocket-propelled grenade and caught fire, according to a U.S. military report. It was not clear if there were any casualties.

In the northeastern city of Mosul, gunmen killed a senior official of Iraq's North Oil Co. on Thursday. Sana Toma Sulaiman, the deputy director of the company's oil products department in Nineveh province, was shot dead as he headed to work, said Hazim Jallawi, a spokesman for the Nineveh governor's office.

The violence came as a top U.S. general said Defense Department officials were not ruling out the possibility that they will need more U.S. troops to secure January's elections, Iraq, but believe Iraqi and perhaps international troops may be able to do the job instead.

"I think we will need more troops than we currently have," Gen. John Abizaid, commander of U.S. troops in the region, said Wednesday. But, he said, Pentagon officials believe the extra needed troops will be Iraqis or international forces.

Allawi, in an address to a joint session of Congress, said elections would be held as scheduled and insisted U.S. and Iraqi forces would rein in the insurgency.

"Elections will occur in Iraq on time in January because Iraqis want elections on time," Allawi said. "We could hold elections tomorrow" in 15 of 18 provinces, he said, even though terror operatives hope to disrupt them.

He cautioned, however, that the election may not come off perfectly. But he assured it will be free and fair, "a giant step" in Iraq's political evolution.

Custody of Female Detainees in Dispute

Earlier, a dispute broke out over the fate of female detainees when the Justice Ministry announced that Rihab Rashid Taha, a scientist who became known as "Dr. Germ" for helping Iraq make weapons out of anthrax, would be freed in the coming days because she was no longer a threat to national security.

Taha and another high-value detainee, Huda Salih Mahdi Ammash, a biotech researcher known as "Mrs. Anthrax," are the only two women the United States says it is holding.

But U.S. and Iraqi officials quickly found themselves at odds over who had custody over the pair, with Iraqi national security adviser Qassim Dawoud saying they were in the hands of Iraqi security forces and that "Iraqi judges decided to release them because they didn't have any evidence."

A U.S. Embassy spokesman disagreed, saying the two "are in our legal and physical custody."

Dawoud on Thursday sought to clear up the matter, saying the two sides were jointly reviewing the status of prisoners, including that of Taha — but not Ammash.

He insisted that the timing of the review and the demands by al-Zarqawi's group to free female prisoners — presumed to mean the two scientists — was a coincidence.

"There is no question of the Iraqi government or multinational forces changing these decisions in the light of the demands of a terrorist group which has taken three hostages and criminally and barbarically murdered two of them," Dawoud said in a statement.

The conflicting U.S. and Iraqi statements raised questions over who has authority in the country, even after the handover of sovereignty to Allawi's interim government in June. U.S. officials have been saying that they have been giving more decision-making power to Iraqis, including over security matters.

Although Taha may well walk free in coming weeks or months, officials were determined not to be seen as giving in to the hostage takers' demands.

The group warned in a Web statement Wednesday that Bigley, 62, would be the next to die unless all Iraqi women are released from jail — though it did not set a deadline as it has in past statements.

The Associated Press contributed to this report.