There was no immediate claim of responsibility for the bombing in Aden's Crater district, which was carried out by an attacker wearing an explosive belt.
Islamist militants, including the Islamic State group, have exploited an 18-month civil war between a Saudi-backed exiled Yemeni government and the Houthi movement to carve out influence in southern Yemen, where they have been recruiting new followers and launching attacks on military targets and senior officials.