Libyan rebel fighters claim they have taken control of 70 per cent of the key western town of Az-Zawiyah, which lies on the highway connecting Tripoli, the capital, to Tunisia.

The opposition says it suffered "many casualties" due to sniper fire from troops loyal to Muammar Gaddafi, the Libyan leader, while taking the town, but that opposition fighters will now march on to Tripoli.

The rebels had previously taken the city, but were pushed out when Gaddafi forces launched a security operation there.

Al Jazeera's Zeina Khodr reports from Az-Zawiyah, Libya.