A suicide bomber drove his explosives-laden car into the entrance of an army base, killing four soldiers in the city in Hadramawt province - a territory with some of the country's dwindling oil reserves. Another militant was killed in clashes that followed.
At around the same time, four militants and two soldiers were killed in a raid on the city's airport before forces regained control of the facility. A civilian woman was also killed in an attack at a nearby agricultural plant.
Washington and Gulf countries are worried that further instability in Yemen could allow Al Qaeda in the Arabian Peninsula (AQAP), the Islamist group's regional wing, to consolidate its position and launch attacks overseas.
AQAP and allied local Islamists have staged attacks on government forces across the country, including many assassinations and car bombs in Hadramawt.
The province and other parts of the former nation of South Yemen have also been rocked by mass protests by a separatist movement.
Seiyun's airport only had two scheduled flights on Thursday, one to Yemen's capital Sanaa and the other to Jeddah in Saudi Arabia, according to flightstats.com.
© Thomson Reuters 2014