The Pentagon told CNN U.S. military forces conducted an operation against Al-Shabaab in Somalia Monday. "We are assessing the results of the operation and will provide additional information as and when appropriate," Pentagon spokesman Rear Adm. John Kirby told CNN.

The announcement comes after troops from the African Union Mission in Somalia and the Somali National Army launched attacks on Al-Shabaab hideouts in the south of the country Saturday.

Following the launch of the offensive, local media reported Al-Shabaab attacked the Somali intelligence headquarters Sunday, killing 10 people. Al-Shabaab fighters attacked the Ex Godka Jilicow prison where 38 of its members were imprisoned.

Al-Shabaab has been attacking Somali military strongholds for more than a year and launching operations within civilian areas in both Somalia and Kenya. Last week, suspected Al-Shabaab militants beheaded a man in Kenya near the resort island of Lamu.