The militant who seems to have mastered only one style in most of their attacks drove an explosive laden car into a Somali army base at Laanta Buur 40km southwest of Mogadishu at about 1:30 am local time on Monday.
The militants after stormed with gunfire.
According to local residents, sound of light weapons and heavy artillery exchanging gunfire was heard.
SNA managed to respond to the attackers with casualties from both sides reported.
Bases of the AU-backed mission in Somalia (AMISOM) have been a regular target of the al Shabaab militant group which seeks to to topple the Western-backed government.
On Sunday SNA raided militants base in souther region of Mogadishu where they killed several militants and destroyed a the base used to store military arsenal.