Al-Qaeda fighters have seized control of an important army base after clashes with soldiers that left at least eight people dead, military officials said.
The officials said at least three soldiers and four al-Qaeda members died in the fighting on Thursday and that at least 15 soldiers were taken hostage.
The base is home to Yemen's 19th Infantry Brigade and is located in the Baihan area in southern Shabwa province.
The officials spoke on condition of anonymity because they are not authorised to talk to reporters.
A Twitter account affiliated with Yemen's al-Qaeda branch, considered by the US to be the most dangerous affiliate of the network, posted images of fighters raising their black flag over the base.
The photographs also show fighters riding in armored vehicles. The images' authenticity could not be independently confirmed but corresponded to events described by the officials.
A statement posted on the group's Twitter account said the attack on the base followed speculation that Shia rebels — who already control the capital, Sanaa, and several northern cities — were looking to establish their presence in southern Yemen as well.
The rebels, known as Houthis, are sworn enemies of al-Qaeda but also oppose the US government.
Their stranglehold on the capital eventually forced President Abd-Rabbu Mansour Hadi to resign, and they subsequently dissolved the parliament as well.
They also recently seized control of central Bayda province, an important gateway to the south, and the oil-rich central Marib province.
Al-Qaeda said in the statement that one of its fighters blew himself up at the base's gates setting off the clashes.
They said the troops in the base eventually surrendered, and have since been freed.