Russia, Ukraine clash over tribute to UN ambassador

Russia and Ukraine clashed on Tuesday over a UN Security Council tribute to long-serving Russian ambassador Vitaly Churkin whose death has triggered an outpouring of grief at the world body.Council ambassadors observed a minute of silence in honor of Churkin and took turns addressing the chamber in the tribute to the 64-year-old diplomat who was Russia's envoy at the United Nations for a decade.Ukraine's Ambassador Volodymyr Yelchenko, who holds this month's council presidency, offered condolenc