House Republicans say former Secretary of State Hillary Clinton bears responsibility for last September's attack on the U.S. Consulate in Benghazi, Libya.
Four Americans, including Ambassador Chris Stephens, died in the attack.
An interim report faults Clinton and other senior State Department officials for approving security reductions at the Benghazi facility.
"Senior State Department officials knew that the threat environment in Benghazi was high and that the Benghazi compound was vulnerable and unable to withstand an attack, yet the department continued to systematically withdraw security personnel," the report said.
The report is also critical of President Obama and White House staff. It accuses them of altering accurate talking points drafted by the U.S. intelligence community in order to protect the State Department.