Military and security sources had originally given a toll of 12 dead and six wounded for the attack in Abyan province.[break]
The blast in the Ahwar district targeted the 111th Brigade´s command centre, the ministry said, adding that its chief, General Mohammed Hussein al-Bakhiti, was seriously wounded.
A military source said the bomber had used an armoured vehicle to carry out the attack.
There was no immediate claim of responsibility.
On Thursday, gunmen suspected of membership in Al-Qaeda carried out two attacks targeting a police post and a security checkpoint near Abyan, military sources said.
A soldier was killed and two others wounded in the attack on the security checkpoint, they added.
Suspected Al-Qaeda fighters carry out frequent attacks in southern Yemen, a lawless region where jihadist groups are active.
On Tuesday, a police officer was gunned in a motorcycle drive-by shooting in Hadramawt province.
A gun battle last month in Abyan province left two suspected Al-Qaeda militants and a pro-government militiaman dead, after a failed attack on the head of a militia that backs the government.
The militias, who recruit from the area´s heavily armed tribes, fought a fierce war alongside the army in mid-2012. They helped to drive Al-Qaeda militants out of the main cities of Abyan, after the extremist network had held them for a year.
Al-Qaeda in the Arabian Peninsula (AQAP) has intensified its attacks on security forces in Yemen, taking advantage of the weakening of the Sanaa central government since a popular uprising that toppled president Ali Abdullah Saleh in 2011.
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