Libya's new government claims to have assumed power, despite a refusal by outgoing Prime Minister Abdullah al-Thinni to stand aside. Earlier, Benghazi was wracked by fighting between militias and renegade troops.
Libya's new government announced that it had taken office on Monday, despite the refusal of some political opponents to recognize newly installed Prime Minister Ahmed Maiteg.
Maiteg - who was himself sworn in as premier by parliament late last month - arrived at the prime minister's office accompanied by police cars. His spokesman said there had been no opposition from security services in gaining entry to the building. A statement said Maiteg had convened ministers for the first time since being elected in May.
Maiteg was chosen to head a transitional government until legislative elections on June 25.
In a brief statement read on live television, Maiteg denounced violence between militant Islamists and army forces in eastern Benghazi on Monday, which killed some 20 people. The 42-year-old businessman vowed to make security his priority.
Battle for Benghazi
Doctors said at least 18 people were killed in the latest violence in Benghazi, which began late on Sunday and continued overnight as military units allied with renegade army general Khalifa Hifter fought with Islamist militias.
Helicopter gunship pilots loyal to Hifter - who is believed to enjoy at least some unofficial support in Tripoli - were said to have bombed Islamist bases around the city, and were themselves targeted with rocket-propelled grenades and anti-aircraft guns.
Maiteg received a vote of confidence from 121 of 200 members of Libya's parliament, the General National Congress (GNC). He is Libya's fifth prime minister since the 2011 toppling of late Libyan leader Moammar Gadhafi, although there are questions about whether his election was legitimate.
'Votes came too late'
Prime Minister Al-Thinni resigned in April - ahead of the May 5 GNC vote. Since then, however, he claims that lawmakers have given him conflicting information about validity of Maiteg's election. It is alleged that some votes were cast after a parliamentary deadline had expired.
Opponents of Maiteg - whose home was targeted in a rocket attack last month - claim he was installed illegally to promote an Islamist agenda.
Al-Thinni has vowed to continue in his post until the matter is resolved, although he had moved to another place of work by the time Maiteg arrived at the prime minister's office.
- AFP, AP, dpa, Reuters