Ukraine Russia Conflict on Crimea - Russia has launched a 'great war' says Ukraine's defence ministry

Russia has launched a 'great war' that could claim tens of thousands of lives, Ukraine's defence ministry warns amid rebel offensive.President Putin says the rebels were trying to push government backs to protect residents from attack.

"A great war has arrived at our doorstep - the likes of which Europe has not seen since World War Two," Ukrainian Defence Minister Valeriy Heletey wrote on Facebook on Monday.