Oct. 17, 2012  -- Authorities today arrested a "lone actor" who thought he was about to blow up the Federal Reserve Bank in New York City's crowded Financial District on behalf of al Qaeda but instead discovered he was the target of a law enforcement sting.

Quazi Mohammad Rezwanul Ahsan Nafis, 21, a Bangladeshi national, allegedly parked a van filled with what he believed to be 1,000 pounds of explosives outside the building in Lower Manhattan near the New York Stock Exchange, and was arrested after he tried to detonate the "bomb" with a cellphone. Officials say there was never any danger to the public.

Nafis faces charges of attempting to use a weapon of mass destruction and attempting to provide material support to al-Qaeda.

Nafis allegedly also threatened to kill a "high-ranking government official," according to the federal complaint. A U.S. official briefed on the case told ABC News the target was Obama.

According to the criminal complaint filed today in federal court in Brooklyn, Nafis came to the U.S. this January in hopes of conducting a terror attack on U.S. soil. He tried to recruit others to form a terror cell inside the U.S., and actively sought out al Qaeda contacts.

According to officials, this summer the would-be terror bomber met a man on the internet who he thought was a fellow aspiring terrorist but was actually an undercover FBI agent.

Nafis allegedly indicated a desire to blow up the Federal Reserve, and he and the undercover agent began planning the bombing. At Nafis's request, say officials, the undercover FBI agent supplied him with 20 50-pound bags of purported explosives known as ANFO, a common industrial explosive, that were used to construct the bomb. Nafis allegedly purchased components for the "bomb"'s detonator.

On Wednesday morning, Nafis met the undercover agent and traveled to a warehouse, where he allegedly said he had a "Plan B" that involved a suicide attack if the bombing was stopped by police. At the warehouse he assembled what he thought was a bomb, and then allegedly parked his van outside the bank on Liberty Street.

He then went to a nearby hotel, where he recorded a video statement that was to be released after the attack. On the video, Nafis allegedly stated, "We will not stop until we attain victory or martyrdom." He then called a cellphone attached to the "bomb," trying repeatedly to detonate the device. The device did not explode, and federal agents arrested him.

"Attempting to destroy a landmark building and kill or main untold numbers of innocent bystanders is about as serious as the imagination can conjure," said Mary Galligan, acting assistant FBI director. "It is important to emphasize that the public was never at risk in this case."

New York Police Commissioner Ray Kelly said the latest terror plot meant that the city was at "15 plots and counting" since 9/11. "Whether al Qaeda operatives like Iyman Faris or those inspired by them like Jose Pimentel, terrorists have tried time and again to make New York City their killing field, [with] the Federal Reserve now added to a list of iconic targets that previously included the Brooklyn Bridge, the New York Stock Exchange, and Citicorp Center."

"Vigilance is our watchword now and into the foreseeable future," said Kelly.

Nafis was arraigned this afternoon in federal court in Brooklyn and remanded without bail.

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