Unknown gunmen assassinated the temporary security director for the eastern Libyan city of Benghazi, state media reported Wednesday.

Col. Faraj al-Dursi was shot dead by three unidentified men in a car in front of his home on Tuesday night, security officials said, according to Libyan state news agency LANA.

The gunmen fled the scene and al-Dursi died shortly after being taken to the Benghazi medical center.

An investigation is under way to find those responsible for the attack.

Dursi was appointed shortly after the September 11 attack on the U.S. consulate, which claimed the lives of U.S. ambassador to Libya Chris Stevens and three other Americans.

Dursi had occupied leading posts under the regime of Muammar Qaddafi, including anti-drugs chief, before joining the revolt against the former dictator when it started in February 2011.

Benghazi has witnessed a series of assassinations and car bombs over the past few months by unidentified assailants targeting mainly security officials who worked under the rule of Qaddafi.

David Petraeus, who recently resigned as director of the CIA, said in closed-door congressional briefings on Friday that the attack on the U.S. diplomatic mission in the country was organized and launched by terrorists affiliated with al Qaeda, according to lawmakers who attended the briefings.

A diplomatic cable sent by Stevens from Benghazi hours before the attack highlighted the rising security threats in and around the city.