Terrorism investigators continue to scramble to try to learn more about the men and circumstances at the center of the chilling terror raids earlier this week in Queens.
And even though law enforcement sources tell NBC New York that there is no evidence that any specific target was discussed officials in New York remain concerned that the city could become a possible target.
Officials said they are still trying to learn more about a Denver man and his associates in both Queens and Colorado, while evidence recovered in Monday's raid has been sent to the FBI lab at Quantico, Va., for additional analysis.
As NBC New York first reported, officials said they recovered a document on how to build a bomb during the searches.
As for the Denver man -- Najibbullah Zazi – he stepped forward Tuesday and through his lawyer told NBC New York that he is not involved with terrorism and that he “loves the U.S.” Zazi, who works as a commuter van driver at Denver airport, had his car and computer seized while he was in New York. No one has been charged with any crime. Zazi’s attorney said the FBI is focusing on the wrong man.
"He loves living here, that's why he brought his family over here," said Denver-based attorney Arthur Folsom, who represents Najibbullah Zazi. "He loves this country."
Investigators also said they seized nine backpacks in the Queens raids but no evidence of explosives were found. Officials said they were looking to see if the backpacks were all bought recently and at the same time.
Several law enforcement officials have pointed out backpacks have been used to conceal bombs in attacks on trains in Madrid and London – but a senior official briefed on the case said there is no evidence of any plot to target New York area trains at this time.
Officials said no warning has been issued in this case because there is no evidence at this time suggesting any of the men discussed possible targets.
One official pointed out how months ago, Homeland Security officials put out an unrelated warning about a possible threat to the Long Island Rail Road. A Long Island man admitted speaking with Al Qaeda operatives overseas about the transit system, prompting the alert.
The same official stressed there is no need for any public threat warning at this time.
On Capitol Hill today, FBI director William Mueller added, "I don't believe there's an imminent danger from what I know of that particular investigation."
Sen. Charles Schumer had asked the FBI chief to reassure New Yorkers and Americans that the case did not pose a ready danger and that any plot was not in an executable stage.
“This recent report put New Yorkers on edge. It came at a time right after 9/11. There are all sorts of rumors going around. I know that this is an ongoing investigation and not much can be said, nor should it, so the investigation is not compromised,” Schumer said at the hearing.
Police Commissioner Ray Kelly said he won't comment on the investigation generally, or the backpacks in particular, saying only the investigation continues. Kelly denied reports suggesting a riff between the FBI and NYPD in the case over whether the NYPD pushed to have the raids happen sooner rather than to conduct surveillance on the men for a while longer.
Yesterday, the New York Post reported that the FBI is miffed with the NYPD for allegedly flubbing the intelligence gathering effort in Queens -- and tipping off the suspect.
Mueller also sought to quell fears assuring lawmakers about the strong cooperation between federal and local law enforcement.
"Our relationships with NYPD in this, and other investigations, could not be better," Mueller added. "New Yorkers are well benefited by the work of NYPD and Ray Kelly in making the city safe. In situations where there are investigations being conducted, we have a very good working relationship and we continue that relationship."