Thousands of malnourished Somali women and children are fleeing into Ethiopia to escape Islamist militants who are taxing them and seizing their food, animals and land.
The al Qaeda-linked group confirmed the executions, which took place on in Jamame district of lower Jubba region, Somalia.
Suspected Al-Shabaab militants have attacked a police camp in the Mandera area on the border with Somalia.
Al Shabaab said its fighters killed dozens of Kenyan troops when the Islamist group attacked a remote military base in Somalia on Friday.
Hunger, malnutrition and death threaten 6.5 million children in the impoverished dry lands of Somalia, Ethiopia and Kenya due to back-to-back droughts.