Libyan rebels say they have taken all of the strategic oil hub of Brega in the east of the country.
The claim, which has not yet been independently confirmed, comes a day after rebels claimed they had seized two other key towns, Zawiyah and Zlitan, as they push their advance on the capital, Tripoli.
Advances by the NATO-backed rebels have threatened to cut off Tripoli, Qaddafi's main stronghold, from main supply routes.
The Libyan government has rejected the rebel claims, with a Qaddafi spokesman, Moussa Ibrahim, saying pro-Qaddafi forces continue to hold the advantage in both Zawiyah and Zlitan.
More than 30 rebels were reported killed and scores injured in recent fighting over Zlitan.
In another development, the rebels announced that Qaddafi's former top aide, Abdul Salam Jalloud, has defected and joined them.
Jalloud was a member of the junta that carried out the 1969 coup that brought Qadaffi to power, and also served as prime minister.
compiled from agency reports