Police tightened the net in a massive hunt for the perpetrator of an attempted car bombing in New York's Times Square, with the federal terrorism experts leading the investigation, authorities said.
The Federal Bureau of Investigation's terrorism task force is working with local New York police to try to catch the would-be bomber, although it remained unclear whether there were any foreign links to the botched attack.
The task force said in a statement that it was seeking "to identify a person who may be in a position to assist with the ongoing investigation."
Part of the probe centered on two people captured on film leaving the scene late Saturday, New York Police Department (NYPD) Commissioner Raymond Kelly said Monday.
One was caught on security camera walking away from the green Nissan Pathfinder that had been left in the teeming tourist area with a large but misfiring bomb inside.
The man looked about in a "furtive" manner, Kelly said, and removed one layer of upper clothing.
Another man appears on footage shot by a tourist, Kelly told CNN. "It's a picture of an individual running north on Broadway," he said.
"These are not suspects. These are people we would like to speak to," he said.
Meanwhile, ABC News reported that authorities were closing in on "a person of interest," described as a naturalized American citizen who hails from Pakistan who just returned from a five-month stay in that country.
The ABC report said there was growing evidence the bomber did not act alone and had ties to "radical elements overseas." It quoted a senior US official saying one of the individuals was a Pakistani-American.
Justice Department spokesman Dean Boyd told AFP authorities are "pursuing every lead to determine the identity and motives of the person or persons responsible," adding that updates on the probe would be provided "as soon as they are available and appropriate to release."
Police were also combing the Nissan sport utility vehicle and its rudimentary bomb consisting of timers, wires, fireworks, gasoline, propane tanks and fertilizer.
CNN television quoted unidentified sources saying that the SUV, which had had its identification marks erased, was bought three weeks ago for 1,800 dollars in a private sale through the Craigslist website.
Mayor Michael Bloomberg said in a statement that police also continued to "scrutinize the videos that we keep getting, images from 82 NYPD cameras in and around Times Square and from scores of privately owned cameras in the area."
He said the fertilizer found in the back of the car -- initially feared to have been similar to an ingredient previously found in powerful homemade weapons -- was determined to be "a non-explosive kind."
While police have a mass of physical evidence that they hope will lead to the driver of the Nissan, there was still little clarity in official statements about the motive or even whether the attack had any foreign link.
New York has been on constant watch for Islamist attacks since the September 11, 2001, airliner attacks that destroyed the World Trade Center, killing almost 3,000 people.
So far, the only group to claim responsibility for the would-be bombing is the Pakistani militant group Tehreek-e-Taliban.
This was quickly dismissed by Bloomberg and Kelly. However, a video emerged showing Pakistani Taliban leader Hakimullah Mehsud -- reported to have been killed months ago -- vowing to attack major US cities.
Another possible indication of jihadist links is the similarity of the botched bombing to a failed double car bomb attempt in London's entertainment districts in 2007.
In Washington, White House spokesman Robert Gibbs said the attack clearly qualified as terrorism. "I would say that was intended to terrorize," he said. "Whoever did that would be categorized as a terrorist."
But Bloomberg was cautious about suggesting an Al-Qaeda or other foreign hand in the incident.
"While there is no evidence that this terrorist act was planned by any terrorist organization, we're just not ruling anything in or anything out," Bloomberg said.
New York is considered a particularly high profile target and authorities here have dismantled a string of alleged terrorist plots since 9/11.
Bloomberg says the city is pushing ahead with plans to expand an intensive network of security cameras linked to police analysts.
The system is being set up in lower Manhattan, including around Wall Street, and will spread to Midtown areas like Times Square, the mayor said.
Copyright 2010  AFP Global Edition
