BENGHAZI, Libya (Reuters) -Libya's political crisis looked set to worsen on Thursday with a risk of a return to fighting or territorial division as a new government preparing to take office accused the incumbent administration of abducting two proposed cabinet members.

       Parliament has been preparing to swear in Fathi Bashagha's government later on Thursday in Tobruk, in eastern Libya. The incumbent prime minister Abdulhamid al-Dbeibah in the capital Tripoli, in the west has vowed not to cede power.

       Two sources close to Bashagha said an armed group affiliated with Dbeibah in the coastal city of Misrata had seized Bashagha's proposed foreign minister and culture minister as they tried to make the journey by land from Tripoli to Tobruk.

       A spokesperson for Dbeibah's government did not immediately respond to a request for comment about the accusation.

       The sources asked not to be named because they were not authorized to speak to the media. Bashagha's office said it "confirmed the kidnapping of the foreign affairs and culture ministers."

       The parliament moved to seize control of government and the political process after a scheduled election collapsed in December.

       Armed groups affiliated with opposing factions have been mobilising in the capital over recent weeks and many Libyans fear the political crisis will plunge the country into violence, division and chaos after a year and a half of comparative calm.

       Overnight, the United Nations raised doubts over the validity of the parliament's move to install the new prime minister, saying it was concerned by reports that the procedure "fell short of the expected standards".

       (Reporting by Ayman al-Warfali, writing by Angus McDowall; Editing by Raissa Kasolowsky and fRank Jack Daniel)