From Amnesty International:
Twelve former detainees were shot dead on 9 or 10 June 2016, shortly after an order by the Libyan Supreme Court for their ‘release under supervision’ from the al-Baraka prison (commonly known as al-Ruwaimi) in Tripoli.
Amnesty International is calling on Libyan authorities to immediately act on their pledge to conduct an investigation into the killings and break Libya’s endemic cycle of impunity by holding to account those found to be responsible.
The investigation must be thorough and impartial and have the necessary powers and resources to be effective.
According to the report:
"The bodies of the 12 men were dumped in different parts of Tripoli and found by passers-by who alerted the authorities. The men belonged to a larger group of 19 detainees due for release on 9 June, some of whom have been in pre-trial detention since 2011. They were accused of being former members of the al-Gaddafi government’s revolutionary guard and being involved in the brutal crackdown on demonstrators during the 2011 Libyan uprising.
"According to one of the victims’ family members, following the announcement of the detainees’ release, the families were contacted and advised to produce for the authorities the passport of their detained relatives, in order to process their release. The prisoners were never handed over to their families, however. One of the family members interviewed by Amnesty International alleged that the detaining authorities opposed their release.
"He said, “they [the prison authorities] weren’t happy with the decision to release them, so they made sure they didn’t leave that prison alive”.
More details here.
(Source: Amnesty International)