WASHINGTON (Reuters) - The FBI tracked about 108,000 potential terrorism threats or suspicious incidents from mid-2004 to November 2007, but most were found groundless, a Justice Department review found on Friday.

The department’s office of inspector general gave the figure in an audit of the FBI’s terrorism case-tracking system, called Guardian, launched in 2002 after the September 11 attacks.

“The FBI determined that the overwhelming majority of the threat information documented in Guardian had no nexus to terrorism. However, as a result of information reported in Guardian the FBI initiated over 600 criminal and terrorism-related investigations from October 2006 to December 2007,” the inspector general’s report said.

The report did not discuss the result of the investigations.

FBI policy requires that each threat or suspicious incident reported by the public or other government agencies and law enforcement officers be reviewed to determine whether there is a link to terrorism.

The report expressed concern over delays in the development of a related system, called E-Guardian, for sharing terrorism-related information with local law enforcement. It said the automated Guardian system had improved since it was first implemented, and the number of incidents tracked had grown dramatically.

FBI spokesman John Miller said the agency had implemented steps to resolve concerns and it accepted recommendations made by the inspector general.