Seven people, including six Americans, were under arrest in Miami Friday following a federal investigation into an alleged plot to bomb landmark buildings in the U.S., authorities said.

The arrests were made by the FBI following a raid Thursday. Among the targets of the alleged ring was the Sears Tower in Chicago and a federal office in Miami, officials claim, according to wire reports. More details of the plot were expected to be released in news conferences later Friday.

The alleged terror cell had no apparent ties to al-Qaeda, FBI agents told

The Associated Press

, and consisted mainly of young men in their teens and 20s. The

AP

quoted neighbors of the suspects as saying they described themselves as Muslims and lived in a city warehouse in Miami's Liberty City area.

''There is no imminent threat to Miami or any other area because of these operations,'' Richard Kolko, an FBI spokesman in Washington, told the

AP

.