Libyan Authority for Searching and Identifying the Missing Persons said its teams had dug out 12 bodies from two mass graves in Tarhouna's "5km agricultural project area".
The teams found two bodies in the first mass grave and ten in the second, according to the authority's statement on Wednesday.
Libya's Chamber of Commerce and Industry has caused outrage after receiving a delegation from the United Arab of Emirates (UAE), the primary figure accused of driving Libya into a civil war.
The Association for Families of the Volcano of Rage Martyrs has decried the visit made under the pretext of "trade exchange" and said the chamber should be assessing the businesses affected by Haftar's aggression who launched his offensive on the western region with full and public support from the UAE.
The Tarhuna Victims Association demanded, on Tuesday, the opening of an urgent investigation into the killing of Mohamed Al-Kani, a fugitive from the law who was wanted by the Public Prosecutor on charges of committing numerous murders in the city of Tarhuna in relation to the mass graves discovered in the area.