Ukraine crisis: Inside town emptied by rebel forces
3 September 2014 Last updated at 09:13 BST
Ukraine's defence minister has accused Russia of launching a "great war" that could claim tens of thousands of lives.
The country has accused pro-Russians of violating a deal reached by the the two sides, by killing as many as 100 Ukrainian troops who were evacuating the town of Ilovaysk via an agreed corridor at the weekend.
Moscow denies sending soldiers into Ukraine.
David Stern reports on Ilovaysk.