The US is on high alert following reports of a possible terror attack ahead of the 9/11 anniversary on Sunday.
Federal authorities are investigating what New York mayor Michael Bloomberg has described as a “specific, credible threat” with New York and Washington the most likely targets.
According to Bloomberg, the threat “has not been corroborated … but we live in a world where these threats must be taken seriously … and we certainly will.”
Security on public transport has been beefed up, while bridges and tunnels are being watched by the police.
According to ABC News, the threat came to light following new information uncovered by the CIA indicating that “three individuals entered the US in August by air with the intent to launch a vehicle-borne attack against Washington, DC or New York around the anniversary of 9/11”
It has been suggested that the alleged plot could be the work of Ayman al-Zawahiri, al-Qaeda’s de facto leader. The Egyptian-born theologian vowed to avenge the death of Osama bin Laden, who was killed by a team of US Special Forces in May.
President Obama and George W Bush are due to attend an anniversary service, along with Bloomberg and former mayor Rudi Giuliani, at ground zero on Sunday.
Speaking at a press conference, Bloomberg said: “We know terrorists view the anniversary as an opportunity to strike again. The NYPD is deploying additional resources around the city … but there is no reason for the rest of us to change anything in our daily routines.”
He also told New York residents: “If you see something, say something.”