Somalia's government has offered an open amnesty to al-Shabab fighters after the rebels made a surprise withdrawal from the capital Mogadishu over the weekend. Al-Shabab, who still govern over much of southern Somalia, have waged a bloody war since 2007 to topple the Western-backed transitional government.

Peter Greste reporting from Mogadishu says African Union troops appear to be thinly strecthed accross the region: "They are now not just controlling a frontline that cuts through the city, they have control the entire city. So that means the physical area they have to man has doubled.