Libyan opposition forces have taken control of an oil refinery outside the town of Zawiya, just 50 kilometres west of the capital, Tripoli.
A BBC crew was taken around the refinery by the rebels who have captured the complex.
They reported was no sign of pro-Gaddafi troops, and dozens of rebel groups could be seen milling around.
This contradicts a statement by the Libyan PM who said earlier that government forces were in control.
The refinery provides supplies for the capital, though much of the fuel used by the Libyan army is smuggled across the border from Tunisia and Algeria.