Nairobi, Kenya - Speaking in Swahili, with a backdrop of lush forest in south-central Somalia, a Kenyan al-Shabab commander encourages young Muslim men to fight in the conflict in Somalia.

"My dear brothers, you must march forward for the sake of Allah," he said. "Some people say they want to go to Afghanistan. If Allah enables you to get there then that is jihad ... and if Allah enables you to get to Somalia, then that is even closer to you."

In the recruitment video released by al-Shabab in February, young men in uniforms compete in running races, a tug of war match and listen to a message from the Quran.