The death toll in the double attack on would-be army recruits in Yemen's temporary capital in the south of the country has risen to 45, hospital officials told dpa.
Islamic State claimed responsibility for the two attacks.
In a statement circulated by social media, the extremist group said an attacker wearing an explosive belt blew himself up among a gathering of soldiers near Badr camp in central Aden close to the house of a senior army officer who leads the recruitment area, killing more than 30 and injuring dozens of others.
The statement added that another attack involving an explosive device outside the camp killed and wounded people the group described as "apostate soldiers."
The statement could not be independently verified by dpa.
Medical sources said more than 30 were wounded in the two attacks, and they expected the number of casualties to rise due to the severity of the injuries.
Earlier reports said that an attack targeted the house of a senior military chief, killing a number of men seeking to enlist in the army who had gathered near the area. The senior military officer escaped the attack unharmed.
A similar attack occurred earlier last week when a suicide bomber killed 27 would-be recruits among a crowd seeking to enlist in the Yemeni army in the south-eastern city of Mukalla. Islamic State claimed responsibility for that attack.
In recent months, Islamic State has taken credit for deadly attacks in war-torn Yemen.
The extremist group has taken advantage of the civil war in Yemen between mainly Shiite Houthi rebels and pro-Hadi forces to make advances.
Yemen is also home to al-Qaeda in the Arabian Peninsula (AQAP), seen as one of the terrorist network's most active branches in the world.
AQAP has expanded its long-standing presence in the impoverished country during the civil war, joining local forces in the fight against the Houthis while also seizing control of territory behind their lines. The conflict has intensified since March 2015 when the rebels advanced on Aden, prompting Saudi Arabia and fellow Sunni allies to start an air campaign in Yemen against the group. Saudi Arabia fears that the rebels will give its regional rival, Shiite Iran, a strategic foothold on the Arabian peninsula.