The U.S. Justice Department filed charges on Wednesday against five suspects, including a top al-Qaida leader, in connection with a plot to blow up the New York City's subway system.

All five defendants were allegedly involved in a plot against the city's subway system, according to an unsealed indictment in Brooklyn Federal Court.

Five suspects include Adnan El Shukrijumah, one of the nation's most-wanted terrorists; Queens resident Adis Medunjanin; Tariq Ur Rehman; Abid Naseer; and a fifth defendant known as "Ahmad," " Sohaib" or "Zahid," said local media.

Attorney General Eric Holder called it "one of the most dangerous since September 11th."

According to the indictment, the suspects planned to use Western operatives to attack a target in the United Kingdom.

Federal prosecutors charge that between September and December 2008, suspects plan to conduct suicide bombings in the subway system using improvised explosive devices. The devices would have been made from hydrogen peroxide, acetone, flour and oil.

Two suspects have pleaded guilty to charges of planning to detonate homemade bombs on the subway.

Shukrijumah, 34, is the top candidates to be al-Qaida's next head of external operations in charge of planning attacks worldwide. He remains at large with a 5-million-U.S.-dollar reward for information leading to his arrest.