Update: Feds :Terror probe is ongoing and "fast-paced"

Reporting from Washington - Authorities today pressed an urgent investigation into whether a Denver-area airport shuttle driver, his father and associates in New York were part of the first operational Al Qaeda-affiliated terrorist plot on U.S. soil since the Sept. 11, 2001, attacks, and what the alleged targets might have been.

 Najibullah Zazi, 24, an Afghan emigre, and his father, Mohammed Wali Zazi, 53, were arrested late Saturday at their town house in the Denver suburb of Aurora. They had undergone three days of questioning by the FBI but had stopped cooperating, authorities said. Also arrested was Ahmad Wais Afzali, 37, of Flushing, N.Y., who was described in court documents as an informant for the New York Police Department.. . . 



. . . FBI agents alleged in court documents today that Zazi had admitted receiving weapons and explosives training from Al Qaeda operatives in Pakistan last year. In court documents and interviews, they also alleged that a handwritten recipe for homemade explosives was found on Zazi's laptop computer, and said it would have produced a bomb of the same size and type used in the deadly 2005 attacks on London's subways and buses. Authorities said they had seized nine new backpacks during last week's raids in New York.