"The death of Eyrow and Omar will not stop the struggle for the supremacy of Allah and the liberation of the holy land of Somalia. We will continue the struggle until the Somali people are free."
Residents of Dusamareb said that the stone house that was targeted had been completely flattened. Bodies could be seen scattered in the streets.
"The bodies were beyond recognition, some of them cut into pieces, and those wounded have been severely burnt," Nur Farah, one resident, told the Associated Press news agency.
"The death of Eyrow and Omar will not stop the struggle for the supremacy of Allah and the liberation of the holy land of Somalia"
Mukhtar Robow Adumansur, an al-Shabaab spokesman
Ahmed Mumin Jama, a local elder, said: "The house was totally destroyed to the ground, also other houses nearby."
Al Jazeera's Mohammed Adow said Eyrow was crucial to the al-Shabaab movement in Somalia.
"Aden Hashi Eyrow, who was in his early 30s, has been the mastermind of the al-Shabaab movement ... [and was] instrumental in the battles al-Shabaab have been waging against Ethiopian and Somali government troops in Mogadishu and outside the capital," he said.
Eyrow, as a member of one of Mogadishu's most powerful clans, was key in bringing influence to the movement, Adow said.
Somali intelligence sources said Eyrow was trained in Afghanistan as a mujahid and later, worked with the Taliban before Afghanistan was attacked by US-led forces.
He then returned to Somalia to establish al-Shabaab as the military wing of the Islamic courts.
The Union of Islamic Courts briefly controlled much of Somalia, until it was ousted by Ethiopian troops backing the transitional Somali government, at the end of 2006.
Al-Shabaab broke from the Union of Islamic Courts when the latter entered into dialogue with the new government in Somalia. The armed group has fought against the Somali government and its Ethiopian allies since early 2007.
Both organisations are on a US list of "terrorist organisations".
Armed Islamist groups have stepped up their attacks on towns in the months, typically taking them for a few hours before withdrawing with captured weapons.
The US military has repeatedly attacked targets in Somalia over the past year.
They fired at least one cruise missile at alleged al-Qaeda targets in southern Somalia in March.
In June, a US navy destroyer shelled suspected al-Qaeda members in the mountainous and remote northeastern areas of Somalia.