The Geneva-based Red Cross says its staff assisted in the recovery of 125 bodies found at 12 different sites in and around Tripoli.
It says remains of 34 people were also recovered from a site in the Nafusa mountain village of Galaa in western Libya.
ICRC spokesman Steven Anderson said Wednesday that more mass graves are being found every week.
The aid group says it is helping ensure the remains are properly recovered so that the identities of the dead can be established and relatives informed.
It said it is not involved in collecting evidence that could be used in war crimes or other legal proceedings.