NEW YORK (CNN) -- Three men accused of plotting to bomb New York's John F. Kennedy International Airport pleaded not guilty Wednesday in U.S. District Court in New York.
A judge denied bond for Kareem Ibrahim, Abdul Kadir and Abdel Nur, who are accused of conspiring to plant explosives to blow up the airport's major jet-fuel supply tanks and pipeline, according to the U.S. Department of Justice.
Russell DeFreitas, a United States citizen and former JFK cargo worker, has already pleaded not guilty.
The defendants are charged with conspiracy to attack a public transportation system, conspiracy to destroy a building with fire and explosives, conspiracy to attack aircraft and aircraft materials, conspiracy to destroy an international airport, and conspiracy to attack a mass transportation facility.
Kadir, a citizen of Guyana who has served as a member of Parliament, also was charged with surveillance of a transportation facility.
Prosecutors say the men tapped into an international network of Muslim extremists to develop the plot and start work toward carrying it out.
A criminal complaint accuses the men of obtaining satellite photos of the airport and using DeFreitas to conduct surveillance and identify potential targets and escape routes.
An informant secretly taped conversations in which DeFreitas allegedly described the symbolic importance of targeting JFK, the complaint says.
"Anytime you hit Kennedy, it is the most hurtful thing to the United States," he allegedly said, according to the complaint. "If you hit that, this whole country will be in mourning. It's like you kill the man twice."
The men arrived in New York Tuesday night after a court in Trinidad and Tobago rejected their attempt to avoid extradition, U.S. attorney's spokesman Robert Nardoza said.
An appeals judge ruled the defendants filed their arguments "out of time," and their lawyers had not filed papers to explain why, so the judge "had no choice" but to strike out their appeal, David West, an attorney in the office of the country's attorney general, said Tuesday.
Their lawyers had earlier argued that Trinidad and Tobago law does not allow for extradition on terrorism conspiracy charges.
The three defendants are scheduled to return to court on August 7 for a status hearing.
New York Police Commissioner Raymond Kelly has said officials were concerned not only about a possible attack on the airport, but also about one on the 40-mile aviation fuel pipeline that runs from a fuel tank farm at JFK through Staten Island, Brooklyn and Queens.
Ibrahim is from Trinidad. Nur and Kadir are from Guyana.
CNN's Susan Candiotti, Julian Cummings and Nkechi Nneji contributed to this report.