New Delhi, Jan. 9 -- Mogadishu's first line of defense against the next militant attack on Somalia 's capital ranges from machine gunners in pick-up trucks to young men in plainclothes manning checkpoints.

One of the leaders is Abdikani Ali Mohamed, a teenage-faced colonel whose authority has grown in the city as Somalia's government tries to dismantle al-Shabab networks.

Mohamed's operatives are so suspicious that even an armored vehicle - the ultimate status symbol beloved by important people - triggers alarm if it has not passed through a checkpoint for days.

"What we have clearly understood is these people ( al-Shabab ) are always evolving," Mohamed said. "The strategy is always evolving in terms of attack mechanisms and the comple...