By John Lee.
The bodies of at least 12 people have been found in Tripoli only days after they were released from prison.
The victims were reportedly loyal to the former Libyan leader Muammar Gaddafi, and had been held at the al-Ruwaimi prison on charges of committing abuses during the uprising in 2011.
Libya's internationally backed Government of National Accord (GNA) issued a statement condemning the murders and ordered an investigation into the deaths.
UN Special Representative Martin Kobler said:
“I am utterly shocked and saddened by this heinous and vile crime, and particularly outraged by family accounts indicating that the victims were savagely beaten and shot in the head and chest several times.
"This crime should be thoroughly and independently investigated and perpetrators must face justice.
"I urge the relevant Libyan authorities to establish a joint national - international investigation and I will follow developments closely."
The Special Representative also pushed for measure to be taken to ensure the safety of all detainees and prisoners, including at the time of their release.
(Sources: Al Jazeera, UN, AFP)
(Murder image via Shutterstock)