WASHINGTON — The FBI lost 160 laptop computers in less than four years, including at least 10 that contained highly sensitive classified information and one that held “personal identifying information on FBI personnel,” according to a new report released yesterday.

The bureau, which has struggled for years to get a handle on sloppy inventory procedures, also reported 160 missing weapons during the same time period, between February 2002 and September 2005, according to the report by the Justice Department inspector general’s office.

In addition to the 10 or more laptops that were confirmed to contain classified information, the FBI could not say whether another 51 computers might also contain secret data, the report said. Seven were assigned to the counterintelligence or counterterrorism divisions, which routinely handle classified information.

“Without knowing the content of these lost and stolen laptops, it is impossible for the FBI to determine the extent of the damage these losses might have had on its operations or on national security,” the inspector general’s office said.

FBI Associate Deputy Director Joseph Ford said in a written response that the report overstated the number of missing weapons by 43, but he acknowledged that “more needs to be done to ensure the proper handling of the loss and theft of laptop computers.”