A Russian flag flies on a howitser as a military convoy withdraws

Russian troops are dying in combat in "large numbers" in eastern Ukraine, where pro-Russian separatists have been fighting against government forces for a year, a NATO official said Thursday.
"Russian soldiers are fighting and dying in large numbers in eastern Ukraine," NATO deputy secretary-general Alexander Vershbow told a conference in the Latvian capital Riga. Moscow has flatly denied the presence of any of its troops in eastern Ukraine.