DETROIT -- Three men arrested inside a southwest Detroit home by federal agents following the Sept. 11 attacks pleaded not guilty Friday to charges that they supported terrorism.

Karim Koubriti, Ahmed Hannan, Farouk Ali-Haimoud and a man known only by the first name Abdella were charged Aug. 28 with conspiring to provide material support or resources to carry out attacks in the United States and upon its allies. The men are accused of operating a terrorist cell out of Detroit and Dearborn apartments.

The FBI is still searching for the fourth suspect.

The indictment alleges the men "operated as a covert underground support unit for terrorist attacks within and outside the United States," as well as a "sleeper" operational combat cell.

The goal was to damage the U.S. economy; provide, train and recruit people; and collect intelligence weapons and false documentation with the aim of attacking people in buildings in the United States, Jordan and Turkey, Local 4 reported.

The indictment says that the three men referred to their associates as "the brothers," and that they were engaged in a global jihad.

The men returned to their jail cells following Friday morning's plea.

Ali-Haimoud's attorney, Kevin Ernst, told Local 4 that the government's case is based on the "uncorroborated and unconfirmed words of a single snitch who was in more trouble than these three men remaining in the case combined."

"There is just no solid evidence of any type of terrorist activity against any of these men," Ernst said.

The lawyer said that the government's charges are an effort to drum up support for the war on terrorism.

The trial for the suspects is expected to begin in January.