The exchange began yesterday on a dark and isolated stretch of a road north of the devastated eastern rebel stronghold of Donetsk, and unfolded as negotiators from both sides held video talks on Skype at reviving stalled negotiations.
The swap involves a total of 222 guerrillas and 145 Ukrainian troops. A final five were due to be handed to Ukraine today from the neighbouring separatist province of Lugansk, according to a rebel spokeswoman.
But Wednesday's acrimonious session broke up after five hours, with a deal reached on only the least contentious of the four agenda points: the prisoner swap.
And Ukraine's suspension yesterday of all bus and rail services to Crimea -- a decision made citing security concerns that effectively severed the peninsula of 2.3 million from the mainland -- added to the hostile tenor of the negotiations.
The video conferences, set to continue today, have so far failed to produce a new date for direct talks.
Some of the captives expressed surprise and joy at having the chance to go home in time for New Year's Eve -- the most cherished of all the holidays celebrated in once-communist eastern Europe.
"They only just told us that this would happen," said a slightly older Ukrainian soldier named Artyom Syurik.
"I am looking forward to seeing my parents and wife. They do not know I am coming."
Yet a rebel named Denis Balbukov sounded defiant as he sat in a Kamaz truck waiting to go home to Donetsk.
But he too was looking forward to going home, adding: "I want to eat fried potatoes and talk to my relatives."
The two warring sides lined up the prisoners some 100 metres apart in the no-man's land between their frontlines, with heavily-armed soldiers and rebels fidgeting nervously in the dark with their automatic rifles.
