Three or four FBI laptop computers are lost or stolen each month and the agency is unable to say in many instances whether information on the machines is sensitive or classified, the Justice Department's inspector general said Monday.

The IG said the FBI is reducing the number of thefts and disappearances of weapons and laptop computers, but the bureau acknowledged in a statement that "more needs to be done."

The Boston field office reported a stolen laptop containing software for creating identification badges. The laboratory division at Quantico, Va., said that a stolen laptop contained names, addresses and phone numbers of FBI personnel. The New Orleans field office reported a stolen laptop that had been used to process surveillance-related electronic digital imaging.

"Perhaps most troubling, the FBI could not determine in many cases whether the lost or stolen laptop computers contained sensitive or classified information," said the Justice Department IG's stated. "Such information may include case information, personal identifying information or classified information on FBI operations."

Of the 160 laptops lost or stolen over a 44-month period, 10 contained sensitive or classified information. The bureau did not have records on whether 51 others contained such data.

In a report five years ago, the inspector general said 354 weapons and 317 laptop computers were lost or stolen during a 28-month review.

The new report found that 160 weapons were lost or stolen during the 44-month period studied.

"Making progress' may seem like a win for the FBI, but it's unacceptable when you're talking about lost weapons and computers with sensitive information," said Sen. Chuck Grassley, R-Iowa.