Al-Shabab Islamist militants targeted an African Union base in central Somalia where Burundian soldiers house, news agencies reported.
Witnesses said there was heavy fighting at the base, which is about 130 km (80 miles) northeast of the capital, Mogadishu.
According to the local military commander, Mohamed Ali, militants launched the attack with a car bomb blast before a heavy exchange of gunfire broke out.
“The terrorists attacked the Burundian army base… there was heavy fighting and casualties inflicted on both sides, but we don’t have more details about this incident so far,” he told AFP news agency.
Al-Shabab said in a statement that it had taken complete control of the base.
This has not been independently confirmed.