A Libyan air force officer was killed Wednesday, and his wife and daughter seriously injured, when a bomb placed under his car exploded in the eastern city of Benghazi, officials said.

In a separate incident, a jihadist leader was killed in the eastern town of Derna, which has been a stronghold of radical Islamist groups since the 2011 uprising that ended Moammar Gadhafi's four-decade rule.

Libya's parliament tasked the interim prime minister on Tuesday with forming a new cabinet, weeks after ousting his predecessor for failing to rein in the lawlessness gripping the country.

Prime minister Abdullah al-Thani, defense minister under ousted premier Ali Zeidan, will face the daunting task of bringing former rebel brigades to heel following the 2011 NATO-backed uprising that ended Moammar Gadhafi's four-decade rule.

Residents of the restive Libyan city of Benghazi observed a general strike Monday to protest against militant violence, as youths blocked streets of the capital in a show of support.

It was the second day of the strike civic groups called to denounce Benghazi's lack of security, and to demand the General National Congress's suspension as well as early elections.

A jihadist group in Libya says it plans to take over security in the restive eastern town of Derna and impose sharia Islamic law, in a posting on Facebook.

Witnesses said the group "Majlis Shura of Islamist Youth in Derna" staged a show of force on Friday, parading through the town armed to the teeth.

Libya's restive eastern city of Benghazi was hit by a day of "civil disobedience" on Sunday that saw some public buildings close and included disruption to air traffic.

Civic groups late on Saturday urged the action to denounce security problems in the nation's second city more than three years after the onset of the revolution that ousted dictator Moammar Gadhafi.

Rebels demanding autonomy for eastern Libya said Thursday they had made progress in talks with the central government on reopening key oil ports that they closed to exports last July.

A rebel spokesman said a first port might reopen as early as next week, raising hopes of an end to the nine-month blockade which has slashed Libyan oil exports from 1.5 million barrels a day to just 250,000 in a massive blow to the economy.

Slain strongman Moammar Gadhafi's son Saadi has asked Libyans for forgiveness in an interview released by prison authorities three weeks after his extradition from neighboring Niger.

The videotaped interview, which was aired by state television late Thursday, was filmed by warders at the capital's al-Hadba prison, where Saadi and several other Gadhafi regime figures are being held, with the blessing of the chief prosecutor, the broadcaster said.

Libya's public prosecutor said Thursday parliamentary chief Nuri Abu Sahmein was being investigated over possible immorality charges linked to a visit to his home by two women.

A video, apparently filmed in secret and which has been circulating online since Wednesday, purports to show Abu Sahmein, head of Libya's General National Congress, answering questions from an unknown man about the presence of the women in his home.

Former Libyan prime minister Ali Zeidan on Tuesday warned that Islamist groups were sabotaging attempts to rebuild his country in order that it become a haven for extremists, in an interview with Britain's newspaper The Times.

Zeidan, who fled to Germany after losing a parliamentary confidence vote earlier this month, said that he was preparing to return "maybe very soon" to help restore order and repel the threat of extremism, two-and-a-half years after the killing of veteran ruler Moammar Gadhafi.

The trial of two sons and dozens of top aides of toppled Libyan dictator Moammar Gadhafi is to open on April 14, a prosecution official said in a surprise announcement Monday.

Seif al-Islam Gadhafi, Saadi Gadhafi and former spy chief Abdullah Senussi are among more than 30 officials from the ousted regime who are to stand trial on charges ranging from murder to embezzlement.