Political uprising sweeping across the Middle East

An African Union mission has arrived in Libya to try to negotiate a ceasefire between rebel forces and those loyal to Colonel Muammar Gaddafi's government.

In Syria, dozens of people are now understood to have been killed during clashes on Friday.

Meanwhile, Cairo's Tahrir Square once again filled with demonstrators calling for Mr Mubarak and his family to be tried for corruption.

From Tripoli, the BBC's Jeremy Bowen has this assessment of political change across the Middle East.