Pakistan has arrested two more foreigners believed to be members of al Qaeda in the last 24 hours, local intelligence officials said this afternoon.
They were the latest in a series of arrests of members of the radical Islamic network in Pakistan, which US officials have said led to information about a plot to bomb buildings in Washington and in the New York area.
Media reports said information gleaned from a computer expert named by the New York Times as Muhammad Naeem Noor Khan and another man named Ahmed Khalfan Ghailani, both apprehended in Pakistan, prompted a high level alert against a possible attack by al Qaeda on US financial institutions.
However much of the information that led to the elevated terror alerts was at least three years old, and US officials are unsure if the group's surveillance continues, according to newspaper reports.
The Washington Post and the New York Times reported that officials were still analysing documents seized late last month after a raid in Pakistan that showed al Qaeda surveillance of specific US targets.
Documents, computers, surveillance reports and sketches were recovered related to the capture of suspected al Qaeda computer expert Muhammad Naeem Noor Khan, also known as Abu Talha, in July, officials said.
Much of the information that resulted from the arrest was compiled before the September 11th, 2001 attacks, the New York Times reported, citing intelligence and law enforcement officials.
Federal authorities said they are unsure whether al Qaeda's surveillance continues, the newspapers reported.
"You could say that the bulk of this information is old, but we know that al Qaeda collects, collects, collects until they're comfortable," a senior government official was quoted in the Times as saying. "Only then do they carry out an operation. And there are signs that some of this may have been updated or may be more recent."
The Post cited officials as saying that much of the information al Qaeda gathered on buildings in Washington, New York and Newark, New Jersey, was obtained through the Internet or other "open sources" available to the general public, including floor plans.
"What we've uncovered is a collection operation as opposed to the launching of an attack," said a senior American official quoted by the Post.
US officials have previously warned of possible attacks before the presidential election in November. The latest warnings on Sunday were of al Qaeda threats to attack symbols of US financial might such as the New York Stock Exchange, World Bank, and International Monetary Fund, among other targets in the New York area and Washington.
In the latest arrests, one man was apprehended at a bus stop in the Hafizabad town in Punjab province, but officials were unsure of his nationality.
"He first said he was from Yemen but later changed his statement to say he was Egyptian," one of the officials, who asked not to be named, said. "We are still checking his nationality. He does not have a passport."
In another swoop, authorities arrested a foreign al Qaeda suspect along with two Pakistanis who were travelling to the eastern city of Lahore, also in Punjab, from the nearby town of Sheikupura on Monday night.