ONE POLICE PLAZA — The man authorities believe is responsible for the Chelsea bombing that injured 29 people acted alone, officials said.
During a press conference about the arrest of suspect Ahmad Khan Rahami, 28, of Elizabeth, New Jersey, Mayor Bill de Blasio and FBI officials said they were not looking for any additional suspects and that there was no larger plot at work.
"I have no indication there is a cell operating here," said FBI Assistant Director William Sweeney Jr., regarding the involvement of a larger terror network in the bombing.
Officials did not disclose the identity of the five people apprehended near the Verrazano-Narrows Bridge Sunday night, but said they were not charged with any crime, were not under arrest and were no longer in custody.
"There was nothing to indicate he was currently on our radar," NYPD Deputy Commissioner for Counterterrorism and Intelligence John Miller said of Rahami.
De Blasio also branded the bombing as terrorism.
"We have every reason to believe this was an act of terror," de Blasio said during the press conference.
The mayor was hesitant to label the bombing as an act of terrorism Saturday night because he said not enough was known about the individual's motives.
"We also want to be up front saying that there is no evidence at this point of a terror connection to this incident. This is preliminary information. It’s something we will be investigating very carefully but there is no evidence at this point of a terror connection," de Blasio said Saturday night.
But other officials, including Gov. Andrew Cuomo, immediately called the bombing a terrorist act.
"A bomb exploding in New York is obviously an act of terrorism," the governor said.
The governor later clarified that while there were no links to "international terrorism," it wasn't clear whether there was a domestic terror link and the incident met the general definition of an act of terrorism.
On Monday morning, during a 7 a.m. appearance on "Good Morning America," the mayor said it appeared the bombing was "leaning" toward being an act of terrorism.
Miller explained that "a bomb going off on the street of New York City is a terrifying act," but said there was a legal definition of terrorism required to charge individuals with it as a crime.
“The basic definition of terrorism on the federal law side is the use of fear, violence or intimidation or the threat of to achieve political or social change," Miller said.
"From the outset of this case, our first priority was to understand who was behind it and to identify that person and bring that person into custody. Our ability to see through the rest of that optic— which is why they did it, what was behind it and whether it was terrorism— required us first to understand who did it."
While sources say Rahami discussed jihadist-related ideas on the internet, his exact motives are not immediately clear and are still under investigation, officials said.
NYPD Commissioner James O'Neill said police also want to speak with Rahami's contacts.
“We’re going to talk to family, talk to friends and see what the connections are," he said. "This is part of the investigation.”