Libya's electoral commission Saturday announced the preliminary results from polls for an assembly to draw up a new constitution, although 13 of 60 seats remained vacant after unrest in several areas stopped voting.

The election to choose the body to draft a new constitution had been billed as a milestone in the country's transition from the 42-year dictatorship of Moammar Gadhafi, but failed to spark enthusiasm among voters.

Gunmen Saturday shot dead a former rebel chief who worked for local councils set up after the 2011 uprising that ousted and killed dictator Moammar Gadhafi, a security official said.

Makhluf al-Ferjani was killed in Gadhafi's home town of Sirte, where he headed the local military council, said the official, speaking on condition of anonymity.

There was confusion Thursday over the trial of Seif al-Islam, son of slain Libyan dictator Moammar Gadhafi, after a scheduled hearing on charges of threatening national security did not take place.

Seif, whose charges stem from the 2011 uprising that ousted his father, last appeared in court in the western city of Zintan on December 12.

A second attempt to organize voting for a constituent assembly in a mainly Tuareg region of southwestern Libya and a jihadist bastion in the east failed Wednesday in the face of persistent insecurity.

The electoral commission said it would not make a third attempt to organize polling in the two areas and parliament would have to decide what to do about the resulting 11 vacant seats in the 60-seat assembly.

The killings of two policemen in Libya's second city Benghazi on Wednesday sparked protests by angry residents who blocked roads and burned tires.

The fatal shootings of the two officers -- one serving, one retired -- came just a day after the U.N. mission in Libya voiced "deep concern" over the near-daily violence plaguing the North African country, particularly the east.

The U.N. mission in Libya voiced "deep concern" on Tuesday over the near-daily violence plaguing the North African country, a day after seven Egyptian Christians were found murdered.

The U.N. Support Mission in Libya called on authorities to make every effort to rein in the rampant unrest, which has hit not only foreign targets but also Libyan civilians and security personnel, as well as polling stations in last week's election to a constituent assembly.

Seven Egyptian Christians were found shot dead near Benghazi in eastern Libya on Monday, security and foreign ministry officials said.

"The bodies of seven Egyptians were found in Jalluta, east of Benghazi," Benghazi security spokesman Ibrahim al-Sharaa told Agence France Presse.

U.S. National Security Adviser Susan Rice said Sunday she had no regrets about remarks she made about an attack in Benghazi, Libya that left a U.S. ambassador dead and sparked a political firestorm.

Four American citizens, including Ambassador Christopher Stevens, were killed in the double raid targeting the U.S. mission and nearby CIA annex on September 11, 2012.

A rocket-propelled grenade exploded Saturday near the Tunisian consulate in the restive eastern Libyan city of Benghazi without causing any casualties or damage.

An Agence France Presse photographer on the scene said the explosion left a crater in the ground in front of the diplomatic mission, and caused minor damage to its outer wall.

Tunisian searchers have found and handed over to Tripoli the black boxes from a Libyan military plane that crashed Friday, killing 11 including a top former jihadist, the government said.

"The transport ministry announces that the two black boxes from the Libyan military aircraft that crashed yesterday in the Grombalia region have been found," a statement on Saturday said.