DEVELOPING: The U.S. ambassador to Libya and three other embassy staff members were reportedly killed Tuesday in an attack on the Libyan city of Benghazi, Reuters and AP report citing a Libyan official.

Spokeswoman Victoria Nuland tells Fox News they do not yet have information on the reports of Ambassador J. Christopher Stevens' death at the moment. The U.S. Embassy in Tripoli says they can only confirm there was an attack on the U.S. compound in Benghazi and one State Department employee was killed, which Secretary of State Clinton said in a statement Tuesday.

The officials tell the Associated Press Ambassador Stevens was killed Tuesday night when he and a group of embassy employees went to the consulate to try to evacuate staff. The protesters were firing gunshots and rocket propelled grenades. All of the officials -- three in all -- hold senior security positions in Benghazi.

They are deputy interior minister for eastern Libya Wanis al-Sharaf; Benghazi security chief Abdel-Basit Haroun; and Benghazi city council and security official Ahmed Bousinia.

Ambassador Stevens was appointed as ambassador to Libya in May 2012, according to an online State Department biography.