The International Committee of the Red Cross said emotional scars among Libyans are "raw" nearly a year after former leader Moammar Gadhafi died after falling into rebel hands.
"Thousands of families" have no idea what happened to relatives who have been missing since the Gadhafi era or during last year's civil war. Some information was gleaned, the agency said, from bodies recovered from a mass grave at the Abu Salim prison, however.
This month, the ICRC announced it was suspending operations in parts of Libya after members of the aid group were attacked.
The agency said seven members of its staff were attacked, but unharmed, by armed gangs in Misurata. The attack marked the fifth time in three months that ICRC staff members were attacked there or in Benghazi.