JUDY WOODRUFF: There are new developments today in the Benghazi consulate attack, as congressional committee leaders turn up the heat on the State Department over the incident, and there are reports that the U.S. is closer to targeting suspected perpetrators.
Margaret Warner has more.
MARGARET WARNER: The attacks that killed American Ambassador Chris Stevens and three colleagues in Benghazi was first described by U.S. officials as an eruption of anger at an anti-Islam film. The Obama administration has since reversed that appraisal and now calls it a well-coordinated terrorist attack.
But questions have mounted over the shifting assessments. And, today, two Republican congressmen, Oversight Committee Chairman Darrell Issa of California and Jason Chaffetz of Utah, leveled new allegations.
In a letter to Secretary of State Clinton, they charged Washington rejected multiple requests for security improvements at Benghazi mission.
They base their assertions on unidentified sources described as multiple U.S. federal government officials. The State Department spokeswoman said the secretary would respond in writing this very day.
VICTORIA NULAND, State Department: Her response is going to be relatively succinct today, as I said, expressing her complete commitment and this building's commitment to work with the Congress to get fully to the bottom of this.
But I don't anticipate she will be able to answer the specific questions today.
MARGARET WARNER: The two congressmen say their committee will hold a hearing next Wednesday on the Libya attack.
Meanwhile, the FBI has sent a team to Libya to determine just what happened. And Secretary Clinton named a review board to assess security arrangements at that U.S. Consulate and others. And while the investigations proceed, The New York Times reported today that the Pentagon and CIA are drawing up contingency plans to kill or capture those believed responsible for the killings.