MOGADISHU, April 1 (Xinhua) -- Somali extremist group, Al-Shabaab, killed two district officials in the restive Mogadishu city on Saturday evening in the latest attack in the Horn of Africa nation.

The insurgents in a statement posted on Sunday on its affiliated media sites said they killed Hassan Indha-Dhuh and Mohamud Moallim Hassan Fagase who were senior district administrators in Hamarweyne District of the Banadir regional administration.

The Somali police confirmed the two deaths, saying investigation is underway to arrest the militants who managed to escape from the scene after committing the heinous act.

Meanwhile, African Union forces repulsed Al-Shabaab attack on an army base in southern Somalia on Sunday.

Isse Mohamed, a military commander said the militants launched an ambush at the forward operating base for the AMISOM (African Union Mission to Somalia) troops in Bulamarer in Lower Shabelle region but faced resistance from the AU forces.

"They (Al-Shabaab) tried to attack an AMISOM base but they failed after they were stopped by the forces," Mohamed told reporters. The official did not, however, state casualties.

Local residents said they heard twin explosions followed by sustained exchange of gunfire but did not confirm the number of casualties.

Aweys Mohamed, a resident, told Xinhua that the attack which happened at midday caused a scare among locals. "We heard a huge explosion followed by gunfire from the area where AMISOM are located. Everyone scampered for safety."

AMISOM could not immediately be reached for comment. Al-Shabaab has in the past conducted similar raids in AMISOM bases killing scores.