NEW YORK (CBSNewYork/AP) -- A fourth suspect was in federal custody and was being questioned late Thursday afternoon, over a possible connection to the Brooklyn Islamic State plot.
Three men were arrested and charged of plotting to help ISIS on Wednesday, and authorities have been looking for other New Yorkers who may have been part of their plot.
The fourth suspect has not been charged but he was being questioned by Immigration and Customs Enforcement agents, sources told CBS2.
Two of the three men already charged, who were arrested in Brooklyn Wednesday, were vocal both online and in personal conversations about their commitment and desire to join the extremists, with one of them speaking of shooting President Barack Obama to "strike fear in the hearts of infidels,'' federal authorities said.
The men were among three charged Wednesday with attempt and conspiracy to provide material support to a terrorist organization.
Akhror Saidakhmetov, 19, was arrested at John F. Kennedy Airport, where he was attempting to board a flight to Istanbul with plans to head to Syria, authorities said.
WEB EXTRA: Read the complaint (.pdf)
Another man, 24-year-old Abdurasul Hasanovich Juraboev, had a ticket to travel to Istanbul next month and was arrested in Brooklyn, federal prosecutors said. The two were held without bail after a brief court appearance.
Police Commissioner Bill Bratton said this was the first public case in New York involving possible fighters going to the Islamic State, but he hinted at ongoing investigations.
"This is real,'' Bratton said. "This is the concern about the lone wolf, inspired to act without ever going to the Mideast.''
A third defendant, Abror Habibov, 30, is accused of helping fund Saidakhmetov's efforts. He was ordered held without bail in Florida. If convicted, each faces a maximum of 15 years in prison.
As CBS2 Political Reporter Marcia Kramer reported, Habibov was arrested in Jacksonville, Florida, and federal agents on Thursday were reportedly looking into a string of mobile phone kiosks that he owned in East Coast malls.
Agents were trying to determine whether his profits financed terror.
Farhod Sulton, of the Brooklyn-based Vatandosh Uzbek-American Federation, knew Habibov personally. He said they disagreed over Habibov's Muslim beliefs.
"We had an argument with the gentleman about the understanding; the way he understands Islam," Sulton said.
Does that mean that Habibov, of Brighton Beach, Brooklyn, had been radicalized years ago? According to Sulton, the answer is apparently yes.
"The way he understands the things – for example, there are some subjects in Islam people understand in a totally different way," Sulton said. "Modern Muslims understand differently than conservatives."
Habibov had moved from Brooklyn a few years ago, and fell out of contact with the borough's Uzbek community, Sulton said.
"We are a community and we greatly regret that this is happening to our community," he said Thursday. "These people, if all these allegations are true, they don't represent our community."
Sulton said at some point, Habibov stopped coming to Uzbek gatherings and he was reading extremist literature, 1010 WINS' Al Jones reported.
"I think there were concerns about how he understands Islam," he said. "He wasn't a crazy guy, he was just a normal guy."
According to a federal complaint, Habibov provided funds for Saidakhmetov and Juraboev to buy airline tickets to fly to Turkey and join ISIS.
Authorities said Juraboev first came to the attention of law enforcement in August, when he posted on an Uzbek-language website that propagates the Islamic State ideology.
Feds: Men Accused In Islamic State Plot Vocal About Beliefs
"Greetings! We too want to pledge our allegiance and commit ourselves while not present there,'' he wrote, according to federal authorities. "Is it possible to commit ourselves as dedicated martyrs anyway while here? What I'm saying is, to shoot Obama and then get shot ourselves, will it do? That will strike fear in the hearts of infidels.''
Federal agents became aware of the message and tracked the IP address back to Juraboev's Brooklyn home. When confronted by agents, Juraboev said he wanted to travel to Syria to fight with ISIS or attack Obama if he could, according to authorities.
Juraboev later said he didn't have the means or plan to attack Obama, according to authorities. Juraboev was also willing to plant a bomb on Coney Island if ordered to do so, authorities said.
The feds had arranged for a confidential informer to befriend the young men and court documents said the informant recorded Saidakhmetov making a threat against law enforcement.
"I will just go and buy a machine gun, AK-47, go out and shoot all police," Saidakhmetov said, according to the complaint. "We will go and purchase one handgun, then go shoot one police officer. Boom. Then, we will take his gun, bullets and a bulletproof vest… then we will do the same with a couple of others. Then we will go to the FBI headquarters, kill the FBI people."
Saidakhmetov's mother took away his passport to try to prevent him from traveling, according to the federal complaint. When he called his mother and asked for it back, she ended up hanging up on him. She had asked him where he wanted to go and he said that a person who had the chance to join the Islamic State group and didn't would face divine judgment.
The informant kept tabs on Juraboev and Saidakhmetov as they visited the travel agency and bought the tickets to Istanbul, authorities said.
Rep. Peter King: Terror Suspects Appeared Committed, Capable
The manager of Nil Travel Agency said one of the men came in to buy the tickets. He said he seemed like an ordinary person and there was no indication of what he had planned.
But the complaint said one of the men said that once he got onto the airplane, he wanted to find an excuse to get into the pilot's cabin and divert the plane to the Islamic State.
U.S. Rep. Peter King (R-N.Y.), who sits on the Homeland Security Committee, said the men appeared committed and capable.
"It does not take a rocket scientist to carry out a terrorist attack," King told WCBS 880's Paul Murnane. "One person with a weapon, with an explosive, can kill five, 10, 15, 20 people -- perhaps even more than that."
While the investigation is ongoing, sources tell CBS2 that agents are seeking to identify others who may have been involved with the men and seeking to join ISIS, CBS2's Marcia Kramer reported.
Also under investigation is the money that Habibov allegedly used to fund the trips. Prosecutors said Habibov owned a total of five mobile kiosks in multiple cities – including Jacksonville and Philadelphia – and had conversations with others about providing funds for Saidakhmetov and Juraboev.
Saidakhmetov's attorney, Adam Perlmutter, said his client was a "young, innocent kid'' who would plead not guilty.
"This is the type of case that highlights everything that is wrong with how the Justice Department approaches these cases,'' Perlmutter said. Juraboev's attorney had no immediate comment.
Brooklyn Borough President: 'These Appear To Have Been Lone Wolves'
Perlmutter also questioned authorities' version of events.
"We know from other cases that you know, informants are enormously manipulative. And these are snippets of conversations that are in the complaint," Perlmutter said. "We do not know the context."
Saidakhmetov is a Brooklyn resident and citizen of Kazakhstan. Juraboev is a Brooklyn resident from Uzbekistan.
Many said the two blended in, working together at a Middle Eastern takeout spot and sharing an apartment in Midwood.
Brooklyn Borough President Eric Adams said the common denominator for those lured to ISIS seems to be youth.
"They appear to be misguided and those who go too far must be arrested, but those who are being fed this information and we can save, we need to do all that we can to save them," he said.
Habibov had been in the U.S. legally, but his visa had expired. He was appointed a public defender on Wednesday.
(TM and © Copyright 2015 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2015 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)
for more features.