Car bomb rips through Yemen's Aden amid shaky ceasefire
The car bomb exploded nearby a local foreign ministry office in the Remy area of the Mansoura district.
Hundreds of worshippers gathered for Friday prayers at a nearby mosque scattered as black smoke rose at the scene.
A man was seen parking a car and fleeing shortly before detonating the device, local media reports.
The recruits were heading to their base in the southern coastal city when the militant infiltrated, in what seems to be a repeat of earlier attacks in Aden.
The temporary capital has seen an increase in violence amid growing security concerns.
In February, a car driven by a suicide bomber exploded at a military checkpoint, killing and injuring many in the northern area of Mosabein, Aden.
Dozens of soldiers were also killed in an earlier attack on a government military camp outside the Presidential Palace in the city, the sources said.
Al-Qaeda in the Arabian Peninsula (AQAP) and Islamic State group militants have taken advantage of 13 months of civil war in Yemen to expand their presence in Aden, where the embattled government is now based.