The Libyan army and its allied forces are preparing to mount an attack on the capital, Tripoli, and the northeastern city of Benghazi, the country’s prime minister says.

"All military forces have been placed under army command to liberate Tripoli and Benghazi soon," Abdullah al-Thani, who has taken refuge in the eastern town of al-Baida along with the new parliament, said on Saturday.

Thani added that the army units have joined ranks with pro-government forces from the town of Zintan to push out rival militants from Tripoli.

The city has been under the control of Fajr (Dawn) Libya- a coalition of several groups- since August.

The new Tripoli rulers have set up a rival parliament and government not recognized by the international community.

The plan for recapturing Tripoli comes after days of fierce battles in the eastern city of Benghazi, where local militants have been fighting the Libyan army and forces loyal to former General Khalifa Haftar.

Forces loyal to Hafter attacked Benghazi on Wednesday in an attempt to purge it from the militants. At least 50 people, including some 20 soldiers, have died in the clashes.

Benghazi has been a war zone since May, when Haftar joined forces with the army and declared war on the militia groups.

Libya plunged into chaos following the 2011 uprising that toppled longtime dictator Muammar Gaddafi. The ouster of Gaddafi gave rise to a patchwork of heavily-armed militias and deep political divisions.

The country has been witnessing numerous clashes between government forces and rival militia groups that refuse to lay down their arms. The groups are now turning their guns on each other in an attempt to dominate politics and the country’s vast oil resources.