The United States on Friday blacklisted Libyan militant groups it accuses of involvement in a 2012 attack on the U.S. mission in Benghazi in which the ambassador and three more Americans died.

The State Department named two groups known as Ansar al-Sharia from the eastern Libyan cities of Benghazi and Darnah and their leaders, and a third affiliated organization from Tunisia.

Libyan Prime Minister Ali Zeidan said Wednesday he would soon announce a major cabinet reshuffle, after calls in the assembly for a vote of no confidence in his government.

"There will be a large ministerial reshuffle next week or the week after," Zeidan said at a news conference.

Self-rule activists in eastern Libya, who have been blockading key oil terminals for months, said Wednesday they would resume exports outside central government control and in defiance of the navy.

The announcement by the head of the self-declared Cyrenaica regional government marked a sharp escalation of its standoff with Tripoli, which on Sunday deployed the navy to prevent two tankers docking in the activist-held eastern port of Al-Sedra to take on crude.

U.S. officials have implicated a former Guantanamo Bay prisoner in the 2012 attack on the U.S. mission in the eastern Libyan city of Benghazi, The Washington Post reported Tuesday.

Militiamen led by Abu Sufian bin Qumu, chief of extremist group Ansar al-Sharia in Derna city, took part in the attack that killed U.S. ambassador Christopher Stevens and three other Americans, according to the daily.

Libya's General National Congress on Tuesday failed to agree on what action to take about the embattled government of Prime Minister Ali Zeidan, a member said.

His administration has been under fire for failing to tackle security problems and end an oil crisis that has dragged on for months after protesters shut key terminals, accusing the authorities of corruption.

Libya's navy has stopped two oil tankers from entering al-Sedra port, the site of a months-long dispute between protesting guards and the government, its National Oil Corporation said Monday.

"The Libyan naval forces on Sunday prevented... a Maltese-flagged tanker in talks with illegal parties from entering the port of al-Sedra to take on crude," said the NOC.

An explosion Monday at a guard post outside a Libyan courthouse in Benghazi killed one judiciary policeman and seriously wounded another, officials said.

Libya's second city, the cradle of the 2011 NATO-backed uprising that toppled Moammar Gadhafi, has seen near daily attacks on security forces in recent months as the weak central government has tried to rein in former rebel brigades turned militias.

A New Zealand woman found murdered with a British companion in Libya was a mother of two visiting her boyfriend, according to media reports Sunday.

The New Zealand foreign ministry confirmed the woman's name as Lynn Howie and said her family had requested no further details be released.

A British man found shot dead in Libya along with a New Zealand woman worked for an equipment maintenance company, an MP said Friday, as police began investigating their murders.

Libyan troops found the bodies of the pair with bullet wounds on a beach in Mellitah, near the city of Sabratha, on Thursday afternoon, according to a security official.

Libyan troops have found the bodies of a British man and a New Zealand woman shot dead southwest of Tripoli, a security source told Agence France Presse Friday.

"The bodies of a British man and a New Zealand woman who had been killed by bullets were found on the beach in Mellitah on Thursday afternoon," the source said.