Is the tide turning against al-Shabab in Somalia?

It is nearly four years since the militant group al-Shabab was driven out of the Somali capital, Mogadishu and it has lost much of the territory it once controlled.

But it retains the ability to carry out high-profile attacks there, and in Kenya.

Somalia's government says it is weakening the leadership of al-Shabab, through a combination of American drone strikes and an amnesty programme for high-level defectors.

The BBC's Andrew Harding has been to Mogadishu - where he had exclusive access to one former al-Shabab commander.