The review will include Pentagon medical and personnel programmes, and US military base security.

Defence Secretary Robert Gates appointed a former Army secretary and an ex-Navy chief to report in 45 days.

The review is in addition to others into the Fort Hood shooting in which 13 people were killed.

Army psychiatrist Nidal Malik Hasan, 39, was shot by police during the incident on 5 November, and remains in hospital. He has been charged with 13 counts of murder.

"The shootings at Fort Hood raise a number of troubling questions that demand complete but prompt answers," Mr Gates said at the Pentagon.

He said the review would look at ways to ensure the safety of military members and their families.