The Ukrainian Defence Ministry said pro-Russian rebel "terrorists" shot down a military plane carry 40 service members and nine crew as it landed at Lugansk.
The ministry statement said that the rebels "cynically and treacherously" downed the plane using anti-aircraft guns and heavy caliber machine guns.
It expressed sympathy to the families of those killed "for their tragic and irreparable loss."
More top news
Some 1,000 counter-protesters blocked 500 neo-Nazi demonstrators as they tried to march to the site of the death of Hitler ally Rudolf Hess.
Clear skies and lighter winds will bring a chilly night for many
Local volunteers joined police in pulling passengers free from the wreckage, with some forced to break windows to reach those trapped inside