The Foreign Intelligence Surveillance Court approved 2,370 warrants last year targeting people in the United States believed to be linked to international terror organizations.

That figure represents a 9 percent increase over 2006. The number of warrants has more than doubled since the terrorist attacks of 2001.

The secret intelligence court was established in 1978 to oversee government requests to conduct surveillance on suspected spies inside the U.S.

The court denied three warrant applications in full and partially denied one, the Justice Department said. Eighty-six times judges sent requests back to the government for changes before approving them.

Those oversight numbers also represent an increase over last year, when the court partially denied only one application and required changes to 73 applications.

Because the workings of the court are secret, however, it's impossible to know whether that increase was due to more court oversight, more aggressive government efforts or simply the nuances of individual cases.