By Tom Doggett

WASHINGTON (Reuters) - Some facilities that handle the U.S. nuclear weapons stockpile misplaced classified bomb components under their care, according to an Energy Department audit.

The department's Inspector General also found there was confusion at the facilities over who was responsible for keeping track of weapons parts and recommended changes in how to better safeguard the parts.

John Broehm, a spokesman for the department's National Nuclear Security Administration that oversees the U.S. nuclear weapons arsenal, said his agency disagreed with the recommendations.

He said the parts, which he declined to identify, were later found.

A summary of the IG's audit -- a little-noticed two-page document released in late July -- found that two of the three sites reviewed did not track "many" classified weapons parts in their custody.

The facilities "could not readily account for or locate some of the items included in our inventory sample," the IG summary said.

The Inspector General's office would not elaborate beyond the summary document or say when the audit was done.

Since the September 11 attacks on New York and Washington, the United States has worried that terrorists may try to buy or steal weapons in other countries to use against it, but the IG's findings raise the possibility of domestic weapons parts getting into the wrong hands.