Al Shabaab attacked Af Urur town this morning. There were few soldiers there and thus al Shabaab captured the town. It is difficult to know the casualties because the telecommunications were cut off," Bari region governor Yusuf Mohamed told Reuters.
The al Qaeda-linked group said it had also killed 61 soldiers after over-running a military base in the town.
"The number could rise since the operation is still underway," Abdiasis Abu Musab, al Shabaab's military spokesman said in a statement.
Musab said their militants had also seized weapons and vehicles from the base.
Al Shabaab's insurgency aims to drive out African Union peacekeepers, topple Somalia's government.