Eight soldiers were killed when a suicide car bomb targeted a Somalia military training camp and attackers then entered the base on foot, the military said Monday.
The car bomb on Monday morning allowed the fighters to infiltrate the Lanta Buro base in Lower Shabelle region, a military officer, Said Mohamed Adawe, told The Associated Press.
"They are still in control of the base," a senior Somali military official said, insisting on speaking on condition of anonymity because he was not authorized to speak to the media.
The Somalia-based al-Shabab extremist group claimed responsibility for the attack, saying it killed 30 soldiers. Al-Shabab also targeted the camp last year with a similar attack, killing more than 15 soldiers.
Residents said they heard heavy gunfire and an explosion Monday before the extremists raised their black banner over the base.
Military officials said the attackers confiscated military vehicles and arms during the attack, which highlights the challenges facing the government and African Union forces in restoring peace and stability in the Horn of Africa nation.
Al-Shabab, which maintains a military presence largely in rural areas, has stepped up attacks on military bases across large parts of south and central Somalia.
The latest attack comes a few days after Somalia's armed forces chief warned troops of possible new attacks by "desperate" extremist fighters who lost key strongholds to Somali troops but later regrouped.
Also Monday, al-Shabab fighters seized partial control of the port town of Marka after government troops withdrew, residents said.
Resident Ali Haji said that fighters entered the town by sea and were patrolling the streets. African Union troops were still in control of parts of the western side of town.
Col. Hassan Ahmed, a senior Somali military official, confirmed the seizure by extremists, without giving details.