A suicide bomber drove a booby-trapped car into an army checkpoint outside Yemen's southern port city of Aden on Sunday, killing at least nine soldiers and wounding 21 others, officials and medical sources said.
The attack, which the government blamed on al Qaeda's Yemen-based wing, comes weeks after the army deployed security forces to surround the coastal city, which lies east of a shipping strait where some 3 million barrels of oil pass daily.
The military has been trying to stop militants from slipping into Aden, after they seized several areas in the neighbouring province of Abyan in recent months and presented a rising challenge to military control.
Unrest in the south has erupted as mass protests seeking to end President Ali Abdullah Saleh's 33-year rule drag into a sixth month, setting off sporadic clashes across the fractious and impoverished country. Saleh is convalescing in Riyadh after a bomb blast in his presidential compound in June. The Defence Ministry said the attacker, who also died in the explosion, hit a convoy at the checkpoint that had been headed to reinforce a military offensive on Abyan's provincial capital of Zinjibar, which the army has been trying to recapture from militants for over a week.