BENGHAZI, Libya — A security official in the Libyan city of Benghazi says police are searching for a senior official who was abducted while investigating the recent assassination of the city's police chief.

The official said Saturday that Lt. Col. Abdel-Salam al-Mahdawi was abducted from a Benghazi street late Wednesday when assailants pulled him from a vehicle. The official spoke on condition of anonymity because he was not authorized to brief the media.

Al-Mahdawi heads Benghazi's criminal investigations unit tasked with looking into the November killing of National Security chief Col. Farag el-Dersi in the city.

Security has deteriorated over the past year in Benghazi, the birthplace of the revolt that unseated longtime ruler Moammar Gadhafi. An attack in September on the U.S. consulate there killed the U.S. ambassador and three other Americans.