FBI agents raided the home of a Colorado man, Wednedsay, whom they believe is an al Qaeda operative.
The suspect, Najibullah Zazi, 24, is an airport shuttle driver. He denies he has any connection to terrorists.
"Of course not. I have nothing to do with al Qaeda. Any link or anything with al Qaeda," Zazi said.
However, authorities said evidence gathered in a series of raids in New York on Monday tells a very different story about Zazi.
In addition to raiding Zazi's home, agents with the FBI's Joint Terrorism Task Force also served a search warrant on his aunt's house.
Agents reportedly found 14 brand new black backpacks they suspect were to be used to carry suicide bombs. They also discovered instructions on Zazi's computers about how to build a bomb with household chemicals.
Agents said suicide bombers who targeted buses and trains in London and Madrid also used backpacks to transport their explosives.
Neighbors of Zazi said the situation was unnerving and surprising.
"I've heard that the FBI from New York is here and the FBI from Washington is here and that it's been the most sensitive terror cell investigation since 9/11, and it's five houses from where I live," said resident Barbie Christenson. "I mean their kids went to school with my kids. Their little boy jumped on our trampoline."
"It's surreal. To think that they're investigating a possible terror cell is, you know, I don't know how to describe it," said neighbor John Christenson.
"I mean it doesn't seem like it could be possible in our neighborhood. We've seen cars in the area quite a bit over the last week you know, a car would sit out and actually we had one in front of our house for a while, and then they'd stay for 10-15 minutes and then they'd leave."