Maj. Gen. Salem Ali al-Quton was traveling in a three-car convoy in the southern city of Aden when the bomber threw himself on the general's pickup truck and detonated his explosives. The commander was killed along with his driver and one of his bodyguards. Five passers-by, including two women, were seriously wounded, the ministry said.
No group claimed responsibility for the attack. The ministry identified the bomber as a Somali national. Aden and the surrounding area have a significant Somali population after tens of thousands of Somalis, fleeing the turmoil in their own country, settled there over the past decades.
Monday's attack came after the army and tribal gunmen fighting alongside the military scored a series of battlefield victories last week in the south, driving al-Qaida militants out of the cities of Zinjibar and Jaar in Abyan province.
Al-Qaida had taken advantage of a security vacuum last year during a popular uprising against Yemen's longtime leader, Ali Abdullah Saleh, to seize large swaths of territory in the strategic south, mostly in Abyan but also in the adjoining Shabwa province. That raised fears it could use the area as a foothold to launch more attacks on U.
The U.S. considers al-Qaida's Yemen branch, known as Al-Qaida in the Arabian Peninsula, to be the terror network's most dangerous offshoot. The Yemeni military's push in the south is supported by U.S. military advisers from a command center manned by dozens of U.S. troops in the al-Annad air base in the southern desert, not far from the main battle zones.
Al-Qaida in Yemen has been blamed for directing a string of unsuccessful bomb plots on U.S. soil from its hideouts. It also emerged last month that the CIA thwarted a plot to down a U.S.-bound airliner using a new, sophisticated explosive to be hidden in the bomber's underwear. The planned bomber was actually a double agent who turned the device over to the U.S. government
Also Monday, Yemen's Defense Minister Mohammed Nasser Ahmed told state TV that the army and tribal fighters entered the town of Azan in Shabwa. Yemeni troops shelled the town for several days to prepare for ground troops to move in and drive out militants.
"Azan and the nearby areas are under the control of the army," said Ahmed. A local official in Shabwa, Yaslem Bajenoub, said most of the militants fled Azan and that town volunteers were guarding the residents.
Ahmed al-Azani, a resident of Azan, told The Associated Press by telephone that the militants left the town in trucks loaded with weapons.