Saying Kar is being held unjustly, the American Civil Liberties Union filed suit against the government yesterday in an effort to secure his release.
Three of those being detained are Iraqi-Americans, Whitman said. The fifth is a Jordanian-American the Pentagon previously had acknowledged holding.
One of the Iraqi-Americans allegedly had knowledge of planning for an attack and a second possibly was involved in a kidnapping, Whitman said.
The third was ''engaged in suspicious activity," Whitman said, declining to be more specific.
They were captured, one each, in April, May, and June.
Whitman said the Iranian-American was arrested with several dozen washing machine timers in his car; such items can be used as components in bombs. Military officials said he was arrested with a cameraman and a taxi driver.
Whitman said the five men do no appear to be connected.
If there are charges, it is not immediately clear whether US courts or Iraq's judicial system would handle the cases.
The International Committee of the Red Cross has visited each of the detainees, Whitman said.
In Los Angeles, Kar's relatives said he was born in Iran and came to the US as a child.
They said Kar, 44, was in Iraq to film scenes for a documentary on Persia's founder when Kar was arrested by Iraqi police at a checkpoint in Baghdad on May 17, a date confirmed by military officials.
''He just had the misfortune to get into the wrong cab," said Steven R. Shapiro, the ACLU's legal director. ''Our position is that if the government has any evidence against him, bring him home and charge in a court and then proceed accordingly."
His family said that an FBI agent in Los Angeles told them Kar had been cleared of any charges and that the washing machine timers allegedly belonged to the taxi driver, who was transporting them to a friend.
''I'm here to beg President Bush . . . to release an innocent boy," Kar's aunt, Parvin Modarress, said at a news conference announcing the suit challenging Kar's detention. ''He went to Iraq to do his dream work, to make a documentary."
The FBI searched Kar's Los Angeles home in May, said a US law enforcement official who spoke on condition of anonymity because the investigation is continuing.
