East Libyan forces pushed on Monday into two districts of Benghazi where they still face resistance, losing at least 12 men in clashes and mine blasts, according to a medical official.
From early morning, roads into the Sabri and Souq al-Hout districts were closed and the sound of heavy weapons and flights overhead by military aircraft could be heard in the area.
The self-styled Libyan National Army (LNA), led by eastern-based commander Khalifa Haftar, has been fighting for three years to take control of Benghazi from Islamists and other opponents.
Earlier this year it secured districts in the south-west of the city after a long siege, but some of the LNA's opponents escaped to join fighters in Sabri and Souq al-Hout, to the north.
"Sabri and Souq al-Hout were stormed today from several directions and control was taken over several points, and numerous booby traps and mines were dismantled during the advance," said LNA commander Fadel al-Hassi.
A car bomb aimed at LNA forces had been destroyed before it could reach its target, Hassi said.
A medical source said hospitals had received 12 LNA dead and 20 wounded, casualties of clashes or mine explosions. The number of casualties among the LNA's opponents was not clear.