WASHINGTON -- The Education Department acknowledged Thursday that, at the request of the FBI, it had scoured millions of federal student loan records for information about suspected terrorists in the five years since the Sept. 11 attacks.

The data mining -- known as Project Strike Back -- was aimed at determining whether terrorism suspects had obtained college aid illegally to finance their operations.

Authorities said the program was limited to "fewer than 1,000" persons who were considered witnesses or "subjects" of federal terrorism investigations. Most of the searches were conducted in 2001 and 2002; the program was ended in June 2006.

The project -- first disclosed by the Medill School of Journalism at Northwestern University in Evanston, Ill. -- is similar to sometimes secret arrangements FBI made with other federal agencies for information about terror suspects since Sept. 11.

But the idea of the government trolling through massive data bases containing information on ordinary citizens has concerned privacy advocates. The sleuthing comes against a backdrop of even more aggressive moves that terror hunters have made, such as monitoring citizens' phone calls without a court order.

The FBI said searches were triggered by intelligence that terrorists were exploiting student visas and loan programs.

The FBI declined to say how the information was used or whether it led to arrests or prosecutions of suspects.

The Education Department said the FBI sought the information pursuant to an exemption to the federal Privacy Act that authorizes the release of personal data for a criminal investigation.