Gunmen opened fire and killed a police colonel and his aide as their vehicle was passing through a roundabout in the southern Yemeni city of Aden on Saturday, a local security official and witnesses told Reuters.
The attack on Col. Salem Al Milqat, police chief of Tawahi district, occurred in the restive district of Al Mansoura that has seen several assaults on local security officials.
Yemen's internationally-recognised government, now based in Aden, struggles to impose its authority in Yemeni cities.
The Yemeni government is backed by a Saudi-led coalition, which began a military campaign a year ago to prevent the Iran-allied rebel Houthi militia and militants loyal to now-ousted president Ali Abdullah Saleh from taking complete control of Yemen.
On Friday, gunmen attacked an old people's home in the Yemeni port of Aden, killing at least 15 people, including four Christian nuns from India, local officials and medical sources said.