SANA'A — Fifteen Yemeni soldiers were killed yesterday in an attack by suspected al-Qaeda militants in the southern Shabwah province, a local official said.The soldiers were killed when al-Qaeda militants attacked a security checkpoint in Beijan district in the southern province, local council chief Abdallah al-Bahari told Anadolu Agency.A local vigilante was also killed in the attack. No casualties were reported among the attackers.The al-Qaeda group has not claimed responsibility for the attack and Yemeni authorities have yet to comment.Yemen recently launched an offensive against suspected al-Qaeda elements in the south, where the group continues to stage sporadic attacks on army and police targets.Yemen has been dogged by turmoil since pro-democracy protests in 2011 forced autocratic President Ali Abdullah Saleh to step down after 33 years in power.In the three years since, authorities have struggled to restore law and order.