The construction worker who had been held for eight months said "you can do many things" with a nail.
The official release by the militant group's Tripoli wing shows the execution of three spies.
Witnesses say some of the casualties were civilians.
The group of commandos were ordered to leave immediately after arriving at Libyan air base.
The internationally recognized parliament in Tobruk and the rival parliament in Tripoli meet to discuss unity plan.
It was hit by anti-aircraft fire and crashed into the sea near al-Maya.
Libya is caught in a war between its internationally recognized government and an unofficial one controlling Tripoli.
900 people drowned crossing the Mediterranean last week as EU leaders step up efforts to destroy traffickers' vessels.
EU leaders agree to triple naval search mission in Mediterranean following drowning of 900 people in past week.
No reported casualties in latest of embassy attacks in Libya, following assaults on South Korean and Moroccan embassies.
Explosion damages Moroccan embassy in Tripoli the day after gunmen kill two in attack on South Korean mission.
Ahead of sanctions review in June, minister says Libya must be considered as equal a threat to Ukraine.
Fighting between IS and Libya Dawn has forced civilians to flee to Misrata.
As jihadis use cultural vandalism as a weapon of war, fears are increasing for the country's Greco-Roman heritage.
Human Rights Watch outlined the dangers faced by Libya's media in a new report.
Group's success on battlefield and social media inspires offshoots to aid the caliphate's expansion.
The army reportedly has retaken nearly all of Benghazi from the extremist group Ansar al-Sharia.
Images released on social media show a convoy of 4x4s flying jihadist flags in Benghazi.
Today's attack on a hotel frequented by Westerners marks a new development in ISIS's activity in Libya.
At least eight people, including five foreigners, were killed during an attack by gunmen against a luxury hotel in the Libyan capital of Tripoli.
The air strikes were on an airport controlled by a rival administration in the chaotic Libyan capital
A YouTube video shows a group from Misrata taking over the annex of the embassy
ISNA said the Revolutionary Guards had shot down the drone with a ground-to-air missile
A separate battle in the eastern city of Benghazi has complicated Libya's security
British embassy convoy attacked as fierce fighting between rival factions leads to foreign embassy evacuations
Security in the Libyan capital has deteriorated following two weeks of fighting