The Libyan branch of the Islamic State group has released a video purportedly showing the execution of a Tunisian for spying on behalf of Libya's internationally recognized government.

The footage, released late Monday, showed the man in an orange jumpsuit and blindfolded, kneeling in front of a group of armed men in the eastern city of Benghazi.

Libya's rival authorities have edged closer to forming a unity government as part of a peace deal for the war-torn country, its U.N. envoy said on Sunday.

"After long hours of discussions, we have reached... a consensus on the main elements," Bernardino Leon told reporters in Skhirat near the Moroccan capital, where talks resumed last week.

A car bomb exploded near a prison in the Libyan capital where former officials of Moammar Gadhafi's regime, including the dictator's playboy son, are being held, an official said.

"A car bomb exploded close to the Al-Habda al-Khadra prison, where there is also an interior ministry brigade headquarters," prison spokesman Othman al-Ghellani told AFP.

Algeria, Niger and Chad on Sunday stressed the urgency of creating a national unity government to solve the conflict in their neighbor Libya.

Algeria's African affairs ministers and the foreign ministers of Niger and Chad stressed the importance of such a government "to preserve Libya's unity and territorial integrity and its people's cohesion."

At least 30 migrants are feared to have drowned off Libya after their dinghy began to sink, the International Organization for Migration (IOM) said Friday.

Some 91 survivors rescued by the Italian coastguard on Thursday said the boat had been carrying between 120 and 140 people when it began to deflate, sparking panic and tipping some people overboard.

Libya's coastguards said they rescued more than 100 African migrants on an overloaded rubber dinghy bound for Europe that was about to sink off the coast of Tripoli on Thursday.

"We rescued 104 African migrants, including 14 women. Most of them were from Sierra Leone and Nigeria," Lieutenant Mohamad Dandi of the Tripoli coastguard told AFP.

More than 13 million children are being denied an education by Middle East conflicts, the U.N. said Thursday, warning "the hopes of a generation" would be dashed if they cannot return to classrooms.

In a report on the impact of conflict on education in six countries and territories across the region, the United Nation's children fund UNICEF said more than 8,850 schools were no longer usable due to violence.

Libya's Tripoli-based authorities said Wednesday they had not yet decided whether to take part in crucial peace talks, a day before their expected start in Geneva.

The talks, aimed at ending more than a year of violence and political chaos in the North African country, are due to take place in the Swiss city on Thursday and Friday.

A large weapons stash was discovered Tuesday on a cargo ship off the Greek island of Crete, a police source said, with initial information suggesting it sailed from Turkey and was headed for Libya.

Greek port police boarded the Haddad 1 and found shotguns in a shipping container, although no details were given on the other weapons found.

The Islamic State jihadist group on Tuesday claimed a car bomb attack against an oil company co-owned by Italy's Eni in the Libyan capital that wounded one person.

IS said in a statement on Twitter that one of its "security detachments targeted the headquarters of Mellitah Oil and Gas with a car bomb in the Dhahra district in downtown Tripoli".