US air strike said to kill 13 al Shabaab militants in Somalia

(Reuters) - The U.S. military on Sunday said it believed it had killed 13 al Shabaab fighters in southern Somalia in what it called a "collective self-defense airstrike" at the request of the Somali government.

The Somali government and allied forces began a campaign a year ago to that has pushed al Shabaab, an al Qaeda-linked group, out of parts of the center of the country, although the group continues to carry out major attacks.