Miami ? Ruling that they posed too great a risk to the community to be released, a federal judge denied bond Wednesday to six men accused of plotting to blow up Chicago’s Sears Tower and conspiring to help al-Qaida attack several federal buildings.

“The charges against each of the defendants are serious charges and constitute counts of violence,” U.S. Magistrate Judge Ted Bandstra said, adding that it was “not relevant that the plans appear to be beyond the abilities of the defendants.”

The six, who have pleaded not guilty, were arrested June 22 in Miami as part of an undercover FBI sting. They are accused of seeking to support what they thought was an al-Qaida operative’s effort to bomb FBI buildings in Chicago, Los Angeles, Miami, New York and Washington.

A seventh man arrested in the case and charged in Atlanta was also being held without bond.