KAMPALA, Uganda -- An American who serves as a commander with a Somali militant group says in a new autobiography that he had a "privileged" childhood in Alabama before he joined the al-Qaida linked militants.

Omar Hammami, also known as Abu Mansur al-Amriki, says in his online diary released Wednesday that his "bad temperament" runs in his family and that he showed anger to his teachers when he was in kindergarten.

He says he is releasing the first part of his autobiography now due to the "unpredictable nature" of jihad. He was feared dead last month after he issued a video in March saying his life was in danger because of his disagreements with other militant leaders.

The 28-year-old grew up in Daphne, Alabama. He joined al-Shabab in 2007.

Hammami is wanted by the FBI for his role in militant activities.