People on streets in Yemen's Aden after fighting The streets of Yemen's second city Aden were quiet on Friday, after southern separatists took control of the area earlier this week. An assault Sunday on the embattled government's headquarters by its former allies, Yemen’s southern separatists, has opened a new front in the devastating civil war, a conflict that has created what the United Nations says is the world's worst humanitarian crisis. IMAGES AND SOUNDBITES