Libya conflict: Gaddafi sons have 'left Bani Walid'

Two sons of fugitive Libyan leader Col Muammar Gaddafi were holed up in the town of Bani Walid until Saturday but have now left, according to the head of the interim government.

Mustafa Abdul Jalil told the BBC that Saif al-Islam and Mutassim Gaddafi had been blocking the town's surrender.

Earlier, rebels said negotiations for Bani Walid's surrender had broken down and an assault was imminent.

The BBC's Ben Brown reports from the road between Tripoli and Bani Walid.