Pentagon press spokesman Rear Adm. John F. Kirby said officials were "still assessing the results of the operation," which targeted "a senior Shabaab operative." It was not clear if Ahmed Godane, the suspected target, was a casualty of the strike.
The United States has 100 special operations personnel in Somalia, in support of a 22,000-member army that has driven al-Shabaab from the capital of Mogadishu and other cities.
The attack Monday occurred near the port city of Barawe, where al-Shabaab leaders were meeting. Local Governor Abdikadir Mohammed Nur Sidii said, "I never heard such a huge and deafening blast as the result of the airstrike. It jolted the entire region. We can't confirm how many leaders were killed in the attack. We will confirm later."
Al-Shabaab claimed responsibility for the attack on a Nairobi, Kenya, shopping mall in 2013 that killed 67 people, and Godane has affirmed his group's allegiance to al-Qaida.