a statement-- mall nurishd. the u.n. secretary general criticized all sides for using starvation as a weapon of war. stock markets opened lower again today after hong kong shares closed at their lowest level in nearly three and a half years. u.s. republican presidential hopefuls have taken part in their sixth debate. the two front runners billionaire donald trump and senator ted cruz had clashes. >> reporter: the smaller the field the brighter the spotlight, the nastier the fight. there were sharp attacks on all. >> you're worried most of all about keeping your homes and your families safe and secure. you cannot give hillary clinton a third term of obama's leadership. >> the idea that somehow we're better off today than the day that obama was inaugurated is an alternatively universe. >> the next commander in chief is standing on this stage. i give you my word if i am elected president no service man or service woman will be forced to be on their knees in any nation that captures our fighting men and women will feel the f