. >> reporter: this is baidoa, stronghold of the islamist al shabab group, whose flag flies over most of drought-hit southern somalia. al shabab say they are the legitimate authority of somalia, but america and britain accuse al shabab of being a terrorist organization. caught in the middle, these somalis fleeing the worst drought in 60 years. the old presidential palace has become a refugee camp that's swelling by the day. i'd heard stories of widespread desperation and hunger, especially amongst the children, but nothing prepared me for the shocking scenes once i entered the main hospital. the u.n. says nearly four million somalis are in danger of starvation; the majority of them, children. mohamed janayo is in grave danger. his tiny body shows signs of acute malnutrition and dehydration. his big brother mohamud is there to comfort him, but years of not enough food has left him, too, looking much younger than he is. mohamud is 16. "my parents are out in the camp, looking for food with my four other brothers and sisters," he tells me. it's the same story next door. hamdi tells me she

the problem is, everyone in baidoa has a gun.years ago, in some ways, the situation is the same as it was then. we'll be back tomorrow at 8:00 eastern and again at 10:00.

the problem is, everyone in baidoa has a gun. that was me 20 years ago, in some ways, the situation is the same as it was then. we'll be back tomorrow at 8:00 eastern and again at 10:00. "john king usa" starts right now. >>> good evening, up first tonight, major breaking international news. two administration sources telling me tonight the obama white house is now prepared to explicitly call for the syrian president bashar al assad to step down. the call for regime change the sources tell me is planned for later this week, after united nations security council meeting on the syrian crisis set for tomorrow. these administration sources say the call for assad to step down will be packaged with new treasury department financial sanctions designed to tighten the screws on president assad, his family, and syrian businesses with close ties to the regime. human rights activists say at least 2,000 people have been killed in the regime's brutal crackdown on anti-government protesters over the past several months. as the crackdown has play