Corresponding reports from eyewitnesses indicated that the robbery happened at 12.00 p.m. midday at Dahabshiil bank in Marka town.
The robbers held the bank tellers at gunpoint for about five minutes before disappearing with undisclosed amount of cash.
The robbers in SNA military gears were also wearing masks.
The robbery reports comes after AMISOM warned of Al-Shabaab militant intention of committing atrocities in Somalia disguised in military uniforms so as to create animosity between the peacekeeping troops and Somalia citizenry.
Marka town and it locality are known to harbour Al-Shabaab militants but AMISOM forces in the town is still battling the remnant elements of the Al Qaeda affiliated Islamist group.