Pro-government forces in Libya have regained control of parts of the northeastern city of Benghazi following a fierce battle with militants, military sources say.

The Libyan army backed by forces loyal to retired General Khalifa Haftar mounted an offensive against the militiamen in Benghazi’s east and south on Friday and Saturday, which claimed the lives of at least 36, according to the sources.

The forces reportedly succeeded in retaking military positions and their headquarters that they had lost to the militants in June.

Armed Forces General Staff spokesman Colonel Ahmed al-Mesmari announced that forces loyal to the government have all parts of Benghazi’s east under their control, and are advancing in the city’s south.

Witnesses said Libyan army planes struck several western neighborhoods, including Al-Gawarsha that is regarded as the militants’ stronghold.

Benghazi has been a war zone since May, when Haftar joined forces with the army and declared war on the militia groups. At least 254 people have been killed in clashes in the last two weeks.

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 arms. The groups are now turning their guns on each other in an attempt to dominate politics and the country’s vast oil resources.

Libya’s government and elected parliament moved to Tobruk after an armed group from the town of Misrata seized the capital, Tripoli, and most government institutions in August.

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