Federal prosecutors said the men, who operated out of a warehouse in Miami's blighted Liberty City section took an oath to al-Qaida and plotted to create an "Islamic Army" bent on violence against the United States. Five of those arrested are U.S. citizens.

Attorney General Alberto Gonzales stressed that there was no immediate threat in either Chicago or Miami because the group did not have explosives or other materials it was seeking.

"This group was more aspirational than operational," FBI Deputy Director John Pistole said.

Nevertheless, Gonzales said Thursday's arrests underscored the danger of "homegrown terrorists" who "view their home country as the enemy."

Those arrested ranged in age from 22 to 32 and included a legal immigrant from Haiti and a Haitian who was in this country illegally. Investigators said all members of the alleged plot were in custody on conspiracy charges.

"We are confident that we have identified every individual who had the intent of posing a threat to the United States," said R. Alexander Acosta, U.S. attorney in Miami.

Five of the defendants, including alleged ringleader Narseal Batiste, appeared in federal court in Miami on Friday under heavy security. They were brought in and out in single file, chained together at the wrists and wearing ankle chains.

"It's an example of the philosophy of prevention. These arrests were made during the talking stage, long before any bomb-making stage," said Kendall Coffey, a former U.S. attorney in Florida. "While they may be seen as bungling wannabes, they are potentially dangerous wannabes who, based on the allegations, were pursuing extremely dangerous plans."

Joseph Phanor, the father of defendant Stanley Grant Phanor, said he did not believe "anything they say about" his son.

"This boy, he's not a violent boy. He never got into trouble. He didn't want to kill people," the elder Phanor said. Court records show that his son was convicted of carrying a concealed firearm in 2002 and sentenced to two years' probation.

Prosecutors said Batiste began recruiting and training the others in November. The FBI learned of the plot from someone the defendants tried to recruit, authorities said. The FBI then arranged for an informant of Arabic descent to pass himself off as an al-Qaida operative.

Batiste met several times in December with the informant and asked for boots, uniforms, machine guns, radios, vehicles and $50,000 to help him build an "Islamic Army," the indictment said.

In February, Batiste told the informant that he and his five soldiers wanted to attend al-Qaida training and planned a "full ground war" against the United States in order to "kill all the devils we can," according to the indictment. His mission would "be just as good or greater than 9/11," it said.

Prosecutors said the men plotted to blow up Chicago's Sears Tower, the tallest building in America, and other buildings such as the FBI offices in North Miami Beach. They were charged with conspiracy to destroy the structures and to wage war against the U.S. government.

Batiste and a co-defendant provided the informant with photographs of the FBI building, as well as video footage of other Miami government buildings, and discussed a plot to bomb the FBI building, the indictment said.

Richard Shultz, professor of International Security at Tufts University in Massachusetts, said that groups such as the one in Miami could pose a threat even if they do not make contact with al-Qaida.

"You don't have to go to Afghanistan like the internationalists did in the 1980s to join the jihadist movement; you can do it from your computer in Miami," he said.

Relatives described the defendants as deeply religious people who studied the Bible and took classes in Islam. The elder Phanor said that his son went to classes on Islam with a friend but that he read the Bible at his father's house.

Phanor's brother Michael said his brother owned a construction company and had been friends with this group for about a year. He said they were trying to do community service in the area where they grew up, studying martial arts to keep in shape and setting a good example for neighborhood kids.

No pleas were entered during Friday's court hearing. A federal magistrate scheduled another hearing for next Friday on whether to release the men on bail. He appointed lawyers for Batiste and the four others who said they could not afford one.

Batiste told the court he was self-employed, a father of four and earned about $30,000 a year, but he provided no details.

A sixth defendant, Lyglenson Lemorin, was arrested in Atlanta and made a court appearance there. Phanor did not appear in court. He was in custody on what authorities said was an unrelated state charge.

In addition to Batiste and Phanor, the defendants were identified as Patrick Abraham, or "Brother Pat"; Naudimar Herrera or "Brother Naudy"; Lemorin, also known as "Brother Levi" or Brother Levi-El"; Burson Augustin, also known as "Brother B"; and Rotschild Augustine, or "Brother Rot."

Officials at the 110-floor Sears Tower said in a statement: "Law enforcement continues to tell us that they have never found evidence of a credible terrorism threat against Sears Tower that has gone beyond criminal discussions."

John Huston, executive vice president of the Sears Tower, said that it was "business as usual" at the building Friday and that attendance was good at the skydeck on the 103rd floor.