Four al-Shabab militants were killed and 21 others arrested in joint operations by African Union Mission in Somalia (AMISOM) and the Somali National Army (SNA) in the south-central region last week, the AU mission said on Thursday.

AMISOM said the operation against militants in HirShabelle State also led to the recovery of a cache of weapons, destruction of improvised explosive devices (IEDs), arrests, surrender and neutralization of armed militants. 

Burundi contingent commander Telesphore Barandereka said the upcoming presidential and parliamentary elections are important to Somalia. 

"We are ready to secure them in our areas of responsibility. Our preparations include putting together a special force that will provide security at the venues for the election, the immediate environment and beyond," Barandereka said in a statement issued in Mogadishu. 

"Together with the Somali Security Forces, we have also put in place contingencies to thwart attempts by al-Shabab to disrupt the elections. We also hold regular planning meetings with our partners and other actors to agree on strategies that will create a conducive environment for a secure and peaceful election," he added.