Iraqi militants claimed in a Web posting Monday that they took a Japanese security contractor hostage after ambushing a convoy of foreigners and Iraqi troops in western Iraq.

The Ansar al-Sunnah Army (search) identified the Japanese hostage as Akihito Saito (search), 44, and posted a photocopy of his passport, including his picture, on the group's Web site. It said Saito was "severely injured" in the fight.

The report could not be independently confirmed. Junji Gomakudo, first secretary at the Japanese Embassy in Baghdad, said officials were trying to confirm a report of a kidnapped Japanese citizen but said they did not know if the claim was true.

The group posted other photo ID cards allegedly belonging to Saito, with one identifying him as a security manager of Hart GMSSCO (search), a British-based firm that provides security in Iraq. Another document seemed to be a weapons permit.

Simon Falkner, chief operating officer of Hart, speaking to The Associated Press from London, confirmed there was an ambush Sunday night involving Hart personnel, but would not confirm whether Saito was an employee and if he had been seized.

"There were casualties. It was in a remote area. ... We are at the moment trying to determine what the situation is," he said, refusing to give further details.

The group said Saito was seized after Ansar al-Sunnah fighters ambushed a convoy of five foreign contractors, protected by 12 members of the Iraqi security forces. It claimed all of them were killed in the fight except for the Japanese. It said some of the foreigners were intelligence agents.

The group claimed it ambushed the convoy near Hit, west of Baghdad, and said a fierce battle erupted between the fighters and those in the convoy. Hit is located about 80 miles down the main road from where U.S. forces on Monday have launched a major offensive against militants near the Syrian border. It was not known if the offensive had any connection to the ambush.

In the gunbattle that erupted after the ambush, both sides called in reinforcements, the Ansar al-Sunnah statement said. When U.S. helicopters arrived at the scene, the fighters captured and immediately killed all those in the convoy, except for one, the Japanese man, it said.

It doesn't explain why the man was spared and claims U.S. helicopters lifted the bodies from the scene. The group said it would provide documents and photos of those killed.

The statement made no ultimatum against the hostage and listed no demands.

The Ansar al-Sunnah Army is believed to be a breakaway faction of Ansar al-Islam (search), a Kurdish-led group with links to Al Qaeda. It has claimed responsibility for numerous attacks against Iraqi security forces and twin suicide bombings targeting Kurds in Irbil that killed 109 people in 2004.

Ansar al-Sunnah also has claimed responsibility for the kidnappings of foreigners. In an Internet posting in August, it claimed it killed 12 Nepalese construction workers after taking them hostage. One of the Nepalese was beheaded and 11 others were shot in the head in a video posted on the Internet Aug. 31, 2004.

In Tokyo, an official from the Foreign Ministry's overseas safety division said on condition of anonymity that officials were trying to determine whether the kidnapped person was Japanese.

The U.S. military had no information on the report of a captured Japanese citizen, coalition spokesman Staff Sgt. Nick Minecci said.

Several kidnappings of Japanese over the past two years have fueled further opposition in Japan against the government's deeply unpopular decision to dispatch 500 troops to conduct humanitarian work in the southern Iraqi city of Samawah.

Shosei Koda, a 24-year-old Japanese backpacker visiting Baghdad, was taken hostage last October and beheaded when Japan's government refused to bow to demands by his kidnappers that it withdraw its troops from Iraq. A video posted on the Internet said he was kidnapped by followers of Jordanian militant Abu Musab al-Zarqawi.

Five other Japanese were taken hostage in April 2004 but were later freed unharmed.