General Ahmed Saif al-Yafie, commander of the Fourth Military Region, escaped unharmed when an explosive device planted in his vehicle blew up killing a bodyguard, the source said.
There was no immediate claim of responsibility for the attack and the military official did not blame any group for the bombing.
Aden, declared by the government as Yemen's temporary capital, has been the scene of growing unrest as Al-Qaeda in the Arabian Peninsula, long active in Yemen, and the newly emerged Islamic State group appear to be vying for influence in the port city.
Supported by a Saudi-led coalition, loyalists have regained control of Aden and four nearby provinces in the south since July as deadly battles persist elsewhere across the country.
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In another sign of increasing insecurity, unknown gunmen shot dead a leading member of the pro-government Popular Resistance militia and two of his bodyguards, security officials said. They were killed in a drive-by shooting in central Aden overnight Wednesday and the gunmen fled after the attack, the sources said.
The extremists are occupying government buildings and are frequently seen patrolling several districts of Aden.
They have carried out several deadly attacks, assassinated government officials, and intimidated civilians.
Today, radical Islamist gunmen shut down the faculty of engineering at the University of Aden for the second time in a week, and also kidnapped its dean Saleh Mubarak, students said. The gunmen, who arrived abroad four military vehicles, forced shut the gates to protest against mixing of the sexes on the campus, students said.