Police in U.S. cities are on high alert as New York City prepares to mark the 10th anniversary of 9-11 amid unconfirmed threats of an al Qaeda terror plot to coincide with Sunday's events.
U.S. officials are probing an unconfirmed report that al Qaeda dispatched three men, including two suspects who are possibly American, to detonate a car bomb in New York or Washington at the time of 9-11 memorial events.
But so far, there is no firm evidence that al Qaeda has sneaked any such terrorists into the U.S.
The threat comes as New York City receives a large influx of visitors including dignitaries and the families of victims who died in the Sept. 11 attacks. There are dozens of related events planned around the city on Sunday, including the long-awaited unveiling of a national 9-11 memorial.
Police officers in the Big Apple were ratcheting up security efforts on Saturday, said CNN reporter Allan Chernoff.
"The police put checkpoints in place at locations throughout Manhattan," he told CTV News Channel from NYC. "They were basically stopping cars, having vans and trucks pull over and having the drivers open (vehicles) up."
Chernoff added that the city's police officers are wearing radiation detectors in order to sniff out any possible "dirty" bombs, which are built with radioactive material.
Intelligence officials learned midweek that al Qaeda may be plotting a terror threat on U.S. soil ahead to coincide with the 10th anniversary of 9-11. A CIA informant warned officials that newly-minted al Qaeda leader Ayman al Zawahri asked three men to carry out the alleged plot.
Counterterrorism teams have been working overtime to determine if the threat is real, but so far, haven't been able to confirm it.
President Barack Obama met with his national security team Saturday, but the White House released no new information about possible threats.
Most New York residents have been patient with extra-stringent police measures, said NBC correspondent Tracie Potts.
"People that we've heard from seem to say, ‘We understand why this is happening, we understand the point of it,'" Potts told CTV News Channel from New York City on Saturday.
Similar precautions are being taken in Washington, D.C., the nation's political nerve centre.
The city's police chief has warned that unattended cars parked in suspicious locations or near critical buildings and structures would be towed.
Meanwhile, the FBI says a threat around this time of year is not surprising.
"We're watching," said James McJunkin, FBI assistant director in charge of the Washington field office. "We expect we're going to get an increase in threats and investigative activity around high-profile dates and events."
McJunkin told The Associated Press that the FBI planned months ago to increase staffing around the 10th anniversary of 9-11.
Residents submit to searches, checkpoints
Despite the high security, Chernoff said most NYC residents are unfazed by the fresh terror threat.
"We've been through the worst imaginable tragedy," he said. "The police are always on high alert around here, particularly around anniversary time."
Many New Yorkers have "9-11 fatigue," said Chernoff, explaining that some in the city are worn out by the decade's worth of anxiety that followed Sept. 11, 2001.
Extra security has been in place to protect residents and visitors of both New York City and Washington — the two cities at the centre of the 9-11 terrorist attacks a decade ago. In both cities, residents wove past police armed with assault rifles at security checkpoints on Friday.
"For a lot of New Yorkers, it's ‘Here we go again: more tight security, more anxiety,'" said Chernoff.
Throughout the week, police dogs have been sniffing through train and subway stations. Officers have also been stopping trucks passing through Times Square.
While some bemoan the searches, a former FBI counterterrorism agent says there's no such thing as being too careful.
"[Police] can't afford to ignore any particular lead at this point. They know what's at stake," Jack Cloonan told CTV's Joy Malbon on Friday.
Intelligence analysts have been monitoring the travel patterns and behaviours of people who recently entered the country. While a few people have been singled out for additional scrutiny, none have shown any involvement in a plot, a senior U.S. official told The Associated Press on the condition of anonymity.
With files from The Associated Press
