The Libyan uprising began in the eastern city of Benghazi in February and has since spread further west, in the direction of the capital Tripoli.

Some cities have changed hands several times since fighting began, including the strategic oil port of Brega.

Libyan leader Muammar Gaddafi has kept control of Tripoli and his hometown of Sirte, while opposition-held Misurata has been under siege for weeks.

Source: Al Jazeera