Four men were arrested Wednesday night in what the authorities said was a plot to bomb two synagogues in the Bronx and shoot down military planes at an Air National Guard base in Newburgh, N.Y.
The men, all of whom live in Newburgh, about 60 miles north of New York City, were arrested around 9 p.m. after planting what they believed to be bombs in cars outside the Riverdale Temple and the nearby Riverdale Jewish Center, officials said. But the men did not know the bombs, obtained with the help of an informant for the Federal Bureau of Investigation, were fake.
The arrests capped what officials described as a “painstaking investigation” that began in June 2008 involving an F.B.I. agent who had been told by a federal informant of the men’s desire to attack targets in America. As part of the plot, the men intended to fire Stinger missiles at military aircraft at the base, which is at Stewart International Airport, officials said.
“This latest attempt to attack our freedoms shows that the homeland security threats against New York City are sadly all too real and underscores why we must remain vigilant in our efforts to prevent terrorism,” Mayor Michael R. Bloomberg said in a statement. The mayor was expected to appear at 6:45 a.m. Thursday at the Riverdale Jewish Center morning services, joined by Police Commissioner Raymond W. Kelly.
The charges against the four men represent some of the most significant allegations of domestic terrorism in some time, and come months into a new presidential administration, as President Obama grapples with the question of how to handle detainees at the Guantánamo camp in Cuba.
Rabbi Jonathan I. Rosenblatt, the senior rabbi at the Riverdale Jewish Center, a modern Orthodox congregation in Riverdale, said the police informed him on Wednesday evening that his synagogue was a target of the plot, as well as the Riverdale Temple, a Reform synagogue that is a short distance away, on Independence Avenue. The two buildings are about six blocks apart, each with a plain brick facade. Outside the synagogues on Wednesday night, the streets were eerily quiet.
Rabbi Rosenblatt said in a phone interview that he took the news with “shock, surprise — a sense of disbelief that something which is supposed to belong to the world of front pages and the evening news had invaded the quiet world of our synagogue.”
Jonathan Mark, associate editor of the Jewish Week newspaper who grew up in Riverdale, said the plot would have marked the third time in the past decade that synagogues in Riverdale had been attacked.
Law enforcement officials identified the four men arrested as James Cromitie, David Williams, Onta Williams and Laguerre Payen, all of Newburgh. Some of the men were of Arabic descent, and one is of Haitian descent, according to law enforcement officials. At least three were United States citizens, according to officials. They are all Muslim, a law enforcement official said.
Mr. Cromitie, who is of Afghan descent, had told the informant that he was upset about the war in Afghanistan and that that he wanted to “do something to America.” Mr. Cromitie stated “the best target” — the World Trade Center — “was hit already,” according to the complaint.
In April, Mr. Cromitie and the three other men selected the synagogues as their targets, the statement said. The informant soon helped them get the weapons, which were incapable of being fired or detonated, according to the authorities.
Mr. Kelly told Jewish leaders Wednesday evening that the attackers planned simultaneous attacks, and the men planned to leave the bombs in the cars in front of the two synagogues, drive back to Newburgh and retrieve cellphone-detonating devices and then proceed with the attack on the aircraft at the air base — simultaneously shooting down aircraft while remotely setting off the devices in the cars.
On Wednesday night, they planted one of the mock improvised explosive devices in a trunk of a car outside the temple and two mock bombs in the back seat of a car outside the Jewish center, the authorities said. Shortly thereafter, police officers swooped in and broke the windows on the suspects’ black sport utility vehicle and charged them with conspiracy to use weapons of mass destruction within the United States and conspiracy to acquire and use antiaircraft missiles. They are expected to appear in federal court in White Plains on Thursday.
Around 9 p.m., a law enforcement official said an 18-wheel New York Police Department vehicle blocked the suspects’ black sport utility vehicle at 237th Street and Riverdale Avenue. Another armored vehicle arrived and officers from the department’s Emergency Service Unit took the men out of the truck and handcuffed them.
After the plot was broken up, the team of uniformed officers took the suspects away. They were being held in federal custody late Wednesday in Lower Manhattan.
A federal law enforcement official described the plot as “aspirational” — meaning that the suspects wanted to do something but had no weapons or explosives — and described the operation as a sting with a cooperator within the group.
“It was fully controlled at all times,” a law enforcement official said.
Stewart International Airport is used by the New York Air National Guard and United States Air Force, according to the complaint, and it stores aircraft used to transport military supplies and personnel to the military in Iraq and Afghanistan.
Political leaders responded to the news of the arrests with statements expressing relief.
“This was a very serious threat that could have cost many, many lives if it had gone through,” Representative Peter T. King, Republican from Long Island, said in an interview with WPIX-TV. “It would have been a horrible, damaging tragedy. There’s a real threat from homegrown terrorists and also from jailhouse converts.”
Senator Charles E. Schumer, Democrat of New York, said in a statement: “If there can be any good news from this terror scare it’s that this group was relatively unsophisticated, infiltrated early, and not connected to another terrorist group. This incident shows that we must always be vigilant against terrorism — foreign or domestic.”