BAGHDAD, Iraq — American troops have arrested four Iraqi men in the kidnapping of American journalist Jill Carroll, who was freed in March after 82 days in captivity, an American spokesman said yesterday.

Major General William Caldwell said the four, who were not identified, were arrested in Anbar province, west of Baghdad, but he did not say when. Another American official, Lieutenant Colonel Barry Johnson, said the arrests were made about a month ago.

General Caldwell said Ms. Carroll, who works for the Christian Science Monitor, was held at three locations, including one about seven miles west of Fallujah, before she was freed March 30.

The 28-year-old journalist was kidnapped January 7 in west Baghdad, and her Iraqi interpreter was shot dead. She was released near a Sunni Arab political party office in Baghdad and returned to America on April 2.

The breakthrough came after a Marine lieutenant from the 1st Marine Expeditionary Force identified a house from intelligence reports and photographs that he had seen earlier.

“Sound intelligence was paramount here,” General Caldwell said.

The lieutenant and others in his unit knocked on the door of the house, asked the owner’s permission to look around, and saw “very distinct features” that led them to believe it was likely one of the places where Ms. Carroll had been held, General Caldwell said.

The owner of the house was detained.

“After questioning that suspect, Marines identified additional locations where Jill Carroll was believed to have been held,” General Caldwell said.

General Caldwell said Marines from the 1st Battalion, 25th Marine Regiment, went to a second location and arrested one person.Three others were arrested at yet another place, north of Abu Ghraib, in a raid by the U.S. Army’s 4th Infantry Division, and two hostages were freed.

During the news conference, he showed a video and photographs taken by the Marines of one the homes where Ms. Carroll was believed to have been held. The house had a green gate and floral designs on its green door, while one of the rooms shown inside had little furniture besides a television, a bed, an electric fan, and a water cooler.

Four of the detainees were arrested for involvement in Ms. Carroll’s kidnapping. The role of the fifth suspect was unclear. “U.S. and Iraqi authorities are currently discussing prosecutorial options and will make the determination shortly,” General Caldwell said.

The Christian Science Monitor said it was aware of the announcement in Baghdad and expressed gratitude for American efforts to win her release.

“Like reporters everywhere, we are reassured to hear that several of those who held Jill have been apprehended,” the paper’s editor, Richard Bergenheim, said. “The daily threat of kidnapping in Iraq remains acute for all. Everything possible needs to be done to relieve Iraqis and others of this scourge.”

The kidnappers, a formerly unknown group calling themselves the Revenge Brigade, had demanded the release of all female detainees in Iraq, saying Ms. Carroll would be killed otherwise. American officials did release some female detainees but said the decision was unrelated to the demands.