Three men accused of plotting to travel to Syria to join the Islamic State of Iraq and the Levant (ISIL) group and wage war against the United States have been arrested on terrorism charges.

One of the men spoke of attacking President Barack Obama or planting a bomb at Coney Island, a popular New York tourist attraction, federal officials said.

Wednesday's arrests come after US officials have expressed alarm at the idea that Americans could travel to Syria to fight alongside ISIL or train there and return to the US to carry out attacks against the homeland.

"Several of the defendants planned to commit acts of terror here - in America - if they could not travel, to include killing FBI agents," FBI Assistant Director in Charge Diego Rodriguez said in a statement.  

"This is real," said New York Police Department Commissioner William Bratton at a news conference. "This is the concern about the lone wolf, inspired to act without ever going to the Mideast."

Authorities said that Akhror Saidakhmetov, 19, was arrested at New York's JFK Airport, where he was attempting to board a flight to Istanbul; Abdurasul Hasanovich Juraboev, 24, had a ticket to travel to Istanbul next month and was arrested in New York; and Abror Habibov, 30, accused of helping fund Saidakhmetov's efforts, was arrested in Florida.

Saidakhmetov is a New York resident and citizen of Kazakhstan. Juraboev and Habibov are residents of New York and citizens of Uzbekistan.

They are charged with attempt and conspiracy to provide material support to a terrorist organisation. If convicted, each faces a maximum sentence of 15 years in prison.

More than 20 people have been arrested in the US in the last year for trying to travel to Syria to join ISIL or other armed groups, including six Bosnian-Americans indicted earlier this month.

'Dedicated martyrs'

Federal prosecutors say Juraboev first came to the attention of law enforcement in August, when he posted on an Uzbek-language website that propagates ISIL ideology.

"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?"

Officials said they believed Juraboev planned to travel from Turkey to Syria to join the group. Prosecutors say Saidakhmetov also threatened to carry out an attack in the US if he was unable to join ISIL. Juraboev's plans included attacks against Obama or planting a bomb on Coney Island, officials said.

Federal officials say Juraboev identified Saidakhmetov as a friend and co-worker with a shared ideology. The two exchanged messages on how to get overseas. Saidakhmetov and an informant watched videos of ISIL training camps in Syria, according to court papers.

More than 12,000 foreigners are believed by intelligence services to have travelled from across the world to fight in groups in Syria and Iraq. The volunteers come from at least 81 countries - around one quarter of them reportedly hold Western citizenship.

Source: Al Jazeera And AP