Qaeda-inspired Shebab rebels attacked the presidential palace in Mogadishu overnight, sparking a battle that left at least 20 civilians dead, officials and witnesses said Sunday. The insurgents fired salvos of mortar rounds and closed in on the presidential area even as the world was pledging renewed support to Somali President Sharif Sheikh Ahmed at a conference in Turkey. Sporadic gunfire could heard mid-day Sunday after African Union troops stopped the insurgents in their tracks and defended the shrivelled seaside perimeter housing Sharif's embattled government. “The number of civilians killed during the clashes overnight has reached 11 and it could be higher, because the violent militants using mortars attacked several other positions in southern Mogadishu,” Mohamed Ali Idle, a Somali government security official, said. Ali Muse, head of Mogadishu's ambulance services, said that more civilians were killed in an exchange of mortar fire in the southern neighbourhoods of Holwadag and Black Sea, bringing the death toll to 20. The victims included five members of the same family who were killed when a mortar shell smashed into their home, several witnesses said. “The fighting was very heavy here in Bondhere and Shibis. Many were killed and several others were also injured,” said Abdirahman Ise, a resident.