Intelligence from Pakistan has led to the arrest of over a dozen terror suspects around the globe this week, reports CNN.
Many of the suspects allegedly have links with Osama bin Laden's Al Qaeda.
The CNN report said a man arrested in a British roundup of Al Qaeda suspects is believed to have been on the ground in New York in 2001 conducting reconnaissance of financial buildings.
The terror alert level on Sunday was raised to 'high' for financial services facilities in three US cities.
Intelligence inputs from Pakistan indicate that Al Qaeda training camps have recently been reactivated along Pakistan's border with southeastern Afghanistan.
The inputs, the report said, include overhead surveillance imagery gathered as recently as July.