"Government forces killed Al-Shabaab militant Ibrahim Feili and four of his escorts during confrontations in Kurtunwarey city," Colonel Hassan Mohamed Abu Bakr told reporters in Mogadishu.
He added that the clashes had been part of a "security campaign" on militants in the Lower Shebelle region.
The Al-Qaeda-inspired militant group has yet to confirm Feili's killing.
Meanwhile, a car bomb killed a man and injured two other people in the Somali capital Mogadishu on Friday, a Somali police officer has said.
"The car bomb went off near the Kilometer 4 area as the vehicle headed to downtown Mogadishu," Mohamed Maalin, a Somali police official, told The Anadolu Agency.
"We believe the bomb had been planted in the car as the road from airport is well patrolled," he said.
Maalin added that the man killed in the blast had been an employee of the Turkish embassy in Mogadishu, identified as Mohamed Yare.
Somalia has remained in the grip of on-again, off-again violence since the outbreak of civil war in 1991.
Earlier this year, fractious Somalia appeared to inch closer to stability after government troops and African Union forces – deployed in the country since 2007 – drove Al-Shabaab from most of its strongholds.