Libyan rebels pushing to cut off Tripoli claimed on Thursday to have seized a key oil refinery which is a major source of fuel for the capital.

A rebel commander said late Wednesday that his fighters had managed to "gain control of the refinery" in the town of Zawiyah, some 40 kilometres (25 miles) west of Tripoli.

On Tuesday, rebel forces said their fighters were already in control of most of the port city.