A suicide bomber killed 12 Yemeni soldiers in a military post in the southern province of Abyan on Friday morning, authorities said.
The attacker "drove a booby-trapped car into a site for the security forces," in the Mudiyah district, Mohamed al-Naqib, a spokesperson for the Southern Transitional Council, said.
No group immediately claimed responsibility, but militants linked to Al Qaeda in the Arabian Peninsula (AQAP) have stepped up attacks on military facilities in Yemen.
Al Qaeda's Yemeni branch has used a nine-year conflict between the Iran-aligned Houthi group and a Saudi-backed coalition to bolster its influence in a country that shares a border with Saudi Arabia and sits near major shipping lanes.
Turning to the offensive
The Southern Transitional Council - which is allied with the Saudi coalition and controls large parts of the south which it wants to secede - has stepped up offensives against al-Qaeda elements in Abyan over the past year.
AQAP has survived years of attempted crackdowns by the US military, the coalition and the Houthis, taking advantage of Yemen's mayhem, tribal sympathies and the large stretches of empty territory.