Updated

The FBI says they are offering $10 million for information leading to the arrest of two Americans who are suspected of working with terrorists in Somalia.

The State Department said Wednesday $5 million each will be rewarded for information leading to the capture of al-Shabab members Omar Shafik Hammami and Jehad Mostafa, both of whom are on the FBI's Most Wanted Terrorists List. Al-Shabab is an Al Qaeda affiliate based in Somalia.

A senior FBI official tells Fox 5 both men allegedly “had a persistent interest in targeting U.S. interests” and are “believed to be involved in planning attacks on U.S. persons or property."

However, the official declined to state what, if any, attacks or thwarted attacks the Americans are believed to have been involved in.

Fox 5 reports Mostafa, who is believed to be either 27 or 32, was living in San Diego before moving to Somalia in 2005. He had previously lived in Wisconsin.

The FBI says Mostafa commands foreign fighters for al-Shabab, which has fought for years for control over Somalia. Fox 5 reports he was indicted in California for allegedly providing material support to al-Shabaab.

28-year-old Hammami, a former resident of Daphne, Ala., is believed to have moved to Somalia in 2006.

The FBI says has served as a propagandist for the Al Qaeda-affiliated organization, attracting English-speaking youth with rap songs and video statements, and as a military commander. Fox 5 reports he was indicted in Alabama in 2009 on charges of providing support to a terrorist group.

Hammami reportedly has been involved in a public rift with al-Shabab since last March, when he made a video saying he feared for his safety. Fox 5 reports he has since then spoke out against some of the group's leaders, and his family has said they fear for his life.

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The Associated Press contributed to this report.