Rebels in Libya have launched an assault on an oil refinery to drive troops loyal to Muammar Gaddafi out of a city on the outskirts of Tripoli and consolidate a siege of the capital.
Heavy gunfire was reported near the Zawiya refinery complex, which supplies oil and gas to the Libyan capital.
The BBC reports that control of the town is seen as important because it straddles a major road linking Tripoli to Tunisia.
Colonel Gaddafi is looking isolated, with rebel forces closing in on the capital from the west and south and cutting off its road links to the outside.
Helped by a NATO bombing campaign, the rebels have transformed the battle in the past few days by cutting Tripoli's two main supply routes.
US Defence Secretary Leon Panetta said on Tuesday that Colonel Gaddafi's ''days are numbered''.
