Al Arabiya television network reported five soldiers had been killed. The AU could not immediately confirm that.

The explosion shattered a relative calm in Mogadishu that had endured since the end of a second wave of intense battles between fighters loyal to the Unionof Islamic Courts and the interim government backed by its Ethiopian allies.

At least 1,300 people were killed and entire neighbourhoods levelled in the two bouts of fighting with tanks, rockets and machine guns earlier this year.