Witnesses say bombs have landed near Libyan leader Muammar Gaddafi's compound on Friday morning in the capital, Tripoli.
Reports suggest NATO is behind the attacks.
The opposition says it is advancing in the western mountains around the capital.
Opposition forces said they had seized a military base in Gharyan, located on a main government supply route, and the oil refinery in Az Zawiyah - a key source of fuel supplies to the capital, and the last major barrier before they advance on Tripoli.
Al Jazeera's Zeina Khodr reports from Gharyan.