Six men charged with plotting to blow up the Sears Tower in Chicago and FBI offices have been denied bail.
The Sears Tower is the tallest building in the US
The six have pleaded not guilty to charges they tried to help al-Qaeda wage war against the US government.
Lawyers for the accused said their clients were manipulated by paid FBI informants and that the case against them was overblown.
But a Miami judge refused to free the men on bail, saying they posed a danger to the community.
US Magistrate Ted Bandstra said there was "strong and sufficient" evidence to indicate the suspects had conspired to commit illegal acts on their own, without inducement from government informants.
"I cannot conceive of conditions that could be set that seem sufficient to ensure the safety of the community if released," the judge said.
The men were arrested on 22 June in a poor Miami neighbourhood as part of an undercover FBI sting operation.
Government officials described them after their arrest as "home-grown terrorists" but said they posed no real threat because they had no actual al-Qaeda contacts, no weapons and no means of carrying out the attacks.
Lawyers for the accused said the case against them was overblown
At Wednesday's bail hearing, the lawyer for the alleged ringleader, Narseal Batiste, said his client should be released pending a trial.
"This case is essentially something the government set up to knock down," said the lawyer, John Wylie.
Wylie and the other defence lawyers suggested that the FBI informants continually sought out Batiste to bait him and his group into offering to help conduct surveillance of FBI buildings.
A seventh suspect was arrested and held in Atlanta.