Obama's trip to Kenya raises security concerns

Al-Shabaab militants in East Africa are now posing new worries for the President's trip to Kenya this week. CNN has learned that, in just the last week, the U.S. military has conducted nearly half a dozen secret air strikes in Somalia against al Qaeda's Africa affiliate because U.S. intelligence indicated an attack against Kenyan troops there was imminent, according to defense officials. 

The Pentagon isn't saying much, but the strikes may be timed to the President's visit.