The official says the death toll includes all those killed since a pro-government offensive began on October 15. He spoke on condition of anonymity because he was not authorized to speak to the press.

The fighting has displaced thousands of residents. It comes as Libyans commemorate the three-year anniversary of the capture and killing of the longtime dictator Moammar Gadhafi at the end of Libya's eight-month civil warin 2011.

The oil-rich North African country has since faced mounting challenges tied to a mushrooming of militias initially formed from anti-Gadhafi rebel forces.