A suspected suicide bomber near a security checkpoint leading to the presidential palace has killed at least six people and injured 12 others in the Somali capital, Mogadishu.

The restaurant where the blast occurred and a nearby clinic were badly damaged.

The city has been the scene of a series of attacks in recent weeks as Somalia struggles with a political crisis caused by long-running disagreements over delayed elections.

The electoral stalemate is worrying Somalia's international donors, who fear it could divert attention from the fight against Al-Shabaab, the Al-Qaeda-linked jihadist group that has been battling the weak central government for over a decade.