In October 2011 , following Self_motion preparatory meetings Social_event , Kenyan troops entered Arriving southern Somalia ( `` Operation Linda Nchi '' ) to fight Hostile_encounter Al-Shabaab , and to establish Creating a buffer zone inside Somalia .

Many media outlets also suspected Suspicion the insurgent group 's involvement in the attack Attack based on earlier reprisal warnings Warning it had issued Creating in the wake of Operation Linda Nchi from 2011 to 2012 .