MONS, Belgium, Aug 28 (Reuters) - NATO believes well over 1,000 Russian troops are operating inside Ukraine, a NATO military officer said on Thursday.
"We assess well over 1,000 Russian troops are now operating inside Ukraine," the officer said at NATO's military headquarters in southern Belgium. "They are supporting separatists (and) fighting with them."
Ukraine accused Russia on Thursday of bringing troops into the southeast of the country in support of pro-Moscow separatist rebels. (Reporting by Adrian Croft, writing by Barbara Lewis)