Washington (CNN) - At times angry and choked with emotion, Secretary of State Hillary Clinton on Wednesday took on Republican critics of her department's handling of the September terrorist attack in Libya that killed the U.S. ambassador and three other Americans, but repeatedly distanced herself from a direct role in specific situations.

"As I have said many times since September 11, I take responsibility," Clinton told the Senate Foreign Relations Committee at the first of two long-anticipated congressional hearings Wednesday on the attack that became a major issue in the November presidential election.