The defeat of al-Qaida-linked Islamic militants in Somalia's capital, Mogadishu, has triggered an influx of people escaping starvation in the countryside.  The city has grown from 1.8 million to 2 million residents in eight months, putting a strain on humanitarian agencies trying to help tens of thousands of people living in tent cities with no means of support.  Officials say security is much improved, although there are still sporadic clashes and the occasional suicide bomb attack.