The rebels have taken the residential zone of New Brega.
Libyan rebels said they had captured part of the oil town of Brega on Thursday while their forces in the west pushed toward Zawiyah.
The rebel fighters have encircled Brega, an oil export terminal with a refinery and chemical plant.
Libyan rebels regrouped in Ajdabiya after being scattered by a NATO friendly fire near Brega.
Troops loyal to Muammar Gaddafi on Sunday pounded the western town of Misurata, which has been under its siege for weeks.
US defence secretary said Libyan rebels needed training more than guns.
Forces are swiftly advancing on poorly equipped, loosely organised rebels.
Day in Pics: 4th May
Showbiz World - May 4, 2015
62nd National Film Awards