The U.S. military is holding five U.S. citizens suspected of insurgent activities in Iraq, a Pentagon (search) spokesman said Wednesday.

They were captured separately and don't appear to have ties to one another, spokesman Bryan Whitman (search) said. He declined to identify them, citing a Pentagon policy that prohibits identification of detainees.

Three of those being detained are Iraqi-Americans; another is an Iranian-American; the fifth is a Jordanian-American, Whitman said. The three Iraqi-Americans were captured in April, May and June, officials said. The Iranian-American was captured May 17, one official said, speaking on the condition of anonymity because of the sensitivity of the cases.

One of the Iraqi-Americans (search) allegedly had knowledge of planning for an attack, and another was possibly involved in a kidnapping. The third was "engaged in suspicious activity," Whitman said, declining to be more specific.

Whitman said the Iranian-American was captured with several dozen washing machine timers in his car — items that can be used as components in bombs.

In Los Angeles, relatives identified him as Cyrus Kar, 44, a U.S. Navy veteran who lives in that city. He was in Iraq to film scenes for a documentary on King Cyrus the Great, founder of Persia, when he was arrested at a checkpoint in Baghdad in mid-May, his family said. They also said he has been cleared of wrongdoing and there is no legal authority for his detention.

They said he called them on May 24 and said he had been detained because of a misunderstanding involving a taxi driver who had been driving Kar and his cameraman around Baghdad. Kar was born in Iran but came to the United States when he was a child, according to reports in the Los Angeles Times and The New York Times.

The Jordanian-American was captured in a raid late last year and is suspected of high-level ties to Abu Musab Zarqawi, the Jordanian terrorist and leading Al Qaeda ally in Iraq. Officials announced his capture in March.

All five are in custody at one of the three U.S.-run prisons in Iraq — Abu Ghraib, Camp Bucca or Camp Cropper, Whitman said, declining to provide their precise location. The International Committee of the Red Cross has had access to all five prisoners, Whitman said.

A panel of three U.S. officers rules on whether each prisoner is properly held; that has already taken place for the Jordanian-American. Whitman did not say whether the three Iraqi-Americans or the Iranian-American have been through this process.

Beyond that, their capture presents a complex legal issue for the U.S. government. Whitman said it is not certain whether they will be turned over to the Justice Department for investigation or to the new Iraqi legal system, which has handled the prosecution of other foreign fighters who came to Iraq to fight the U.S.-led occupation and new Iraqi government.

The closest parallel to their situation may be the two American citizens were captured opposing U.S. forces in Afghanistan. Two Taliban foot soldiers, John Walker Lindh and Yaser Esam Hamdi, held U.S. citizenship when they were captured in late 2001.

Lindh, a California native now in his early 20s, pleaded guilty in civilian court to supplying services to the Taliban government and carrying explosives for them. He received a 20-year prison sentence in 2002 and has since sought to have it reduced.

Hamdi was born in Louisiana and grew up in Saudi Arabia. He was held by the U.S. government for three years before being released to his family in Saudi Arabia in October 2004. He gave up his American citizenship as a condition of his release.

Whitman, however, said their cases do not necessarily set a precedent for the handling of the five Americans captured in Iraq because Afghanistan had no functioning government at the time of Lindh's and Hamdi's capture.

The military is holding about 420 non-Iraqis in Iraq, out of more than 10,000 in custody, officials said. Since the Sept. 11 attacks, the U.S. government has held more than 70,000 people in Iraq, Afghanistan and Guantanamo Bay, Cuba.