A military base where US soldiers train commandos in Somalia was attacked Monday, causing casualties, reports say.
Local residents reported heavy blasts and gunfire at Baledogle airport in the southern Lower Shabelle region.
The al-Shabaab militant group claimed responsibility for the attack.
Military officials say the Shabaab have been pushed back.
The base, about 100 kilometres (60 miles) west of the capital Mogadishu, is said to house US special forces, Somali special forces and Ugandan peacekeepers. It is used as a launch site for US drones as well as a training centre.
Separately, an Italian military convoy was hit by an explosion in Mogadishu itself, Italy's defence ministry said. No casualties have as yet been reported.
The US has sharply increased its air strikes against al-Shabaab, which is linked to al-Qaeda, since President Donald Trump took power.
Officials in Somalia say the group has increased its attacks in Mogadishu as retaliation for the air strikes.