A "handful" of men in New York are possible associates of the chief suspect in a suspected plot to use homemade bombs to attack New York City commuter trains, and investigators have them under heavy surveillance, law enforcement officials said Wednesday.
Investigators are still hunting for additional players and expect to make more arrests than just the chief suspect, 24-year-old Denver airport shuttle driver Najibullah Zazi, according to an official who declined to discuss when that might happen or how many people are under scrutiny.
Another official added that the men under surveillance are no longer considered a threat because the plot was thoroughly disrupted. Both officials spoke on condition of anonymity because the investigation continues.
Authorities have said three unnamed people traveled from New York City to suburban Denver over the summer and used stolen credit cards to help Zazi buy products containing hydrogen peroxide and acetone — common ingredients for homemade bombs. The three returned to New York at some point but haven't been accounted for publicly, nor have the "others" who court papers say joined Zazi on a trip to Pakistan last year.
During questioning this month, Zazi told the FBI that he had received instruction on explosives an al-Qaida truing camp in Pakistan, prosecutors said.
Zazi's associates have varied training and backgrounds, but they are disaffected, angry and share a common ideology of extremism, said a senior counterterorrism official in Washington who has been briefed on the investigation and spoke on condition of anonymity.
9/11 anniversary attack?
Zazi — who pleaded not guilty Tuesday to conspiring to use weapons of mass destruction — is the only suspect named so far in what authorities have called a plot that was "international in scope" and may have been intended to coincide with the anniversary of the Sept. 11, 2001, terrorist attacks.
Two other defendants, Zazi's father and a Queens imam in the community where Zazi once lived, have pleaded not guilty to charges they lied to the FBI. Neither faces terrorism charges.
ABC News reported Wednesday that Zazi's friend Naiz Khan is under 24-hour surveillance by federal agents. Khan told ABC that he was not affiliated with al-Qaida and that the dozen black backpacks and small scale found in his apartment were purely coincidental. He says he will continue to cooperate with investigators.
Khan told the AP on Wednesday at his home that he has done nothing wrong and has nothing to fear from the police.
Imam's role in dispute
Investigators said Zazi urgently tried to mix explosives in a Colorado hotel room in early September, then drove to New York to carry out an attack, perhaps on the New York transit system.
The FBI was listening in and becoming increasingly concerned as the Sept. 11 anniversary and a New York visit by President Barack Obama approached, officials said. On Sept. 10, investigators secretly searched Zazi's rented vehicle in New York and found a laptop computer with bomb-making instructions, authorities said.
Around the same time, the FBI alerted the New York Police Department that it was seeking information about Zazi and three other men. NYPD detectives showed photos of the four men to Queens imam Ahmad Wais Afzali — until then considered a reliable police source.
Afzali's lawyer, Ron Kuby, said Wednesday that Afzali told the detectives he recognized Zazi and two other men in the photos. But his client "certainly couldn't shed any light on what Zazi was up to," he said.
The imam was charged with telephoning Zazi to tell him he was being watched, then lying about it. His lawyer has claimed the detectives urged him to get in touch with Zazi.
On Sept. 12, Zazi cut short his New York City visit and flew back to Denver, where he was arrested a week later.