Ukraine and pro-Russian rebels were on Saturday set to complete a swap of hundreds of prisoners as part of a new push for peace that came despite Kiev's decision to cut off key transport links to breakaway Crimea.
The exchange began Friday 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 on Saturday from the neighbouring separatist province of Lugansk, according to a rebel spokeswoman.
Talks mediated by European and Russian envoys in the Belarussian capital Minsk on Wednesday had been supposed to pave the way for a final round on Friday and the signing of a comprehensive peace accord.
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 on Friday 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 on Saturday, have so far failed to produce a new date for direct talks.
The prisoner handover now stands out as a rare example of cooperation between the two bitter enemies.
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.
"I will go back to fighting," the 21-year-old said. "It was alright once we were moved to the detention centre, but to begin with, they really tormented and roughed us up."
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.
One of the 146 Ukrainian prisoners originally brought by the insurgents refused to rejoin his old military unit, and was eventually taken back to Donetsk.
"All of my relatives are in Russia," the ethnically-Russian Alexei Samsonov told AFP. "I consider what the Ukrainian army is doing not to be right."
State security sources in Kiev said the separatists were still holding about 500 government troops after Friday's exchange.
The same source said Ukraine would be willing to swap them for several dozen rebels now languishing in the country's jails.
Smaller such exchanges have been frequent and often involved dozens of men.
Yet they appeared to have built far less trust between the warring parties than Ukraine's Western allies would have hoped.
Simmering East-West tensions over Ukraine prompted the Kremlin on Friday to published a revised and slightly more aggressive military doctrine that decries the "reinforcement of NATO's offensive capacities on Russia's borders".
Moscow accuses Washington of orchestrating weeks of deadly protests in Kiev last winter that toppled an unpopular Russian-backed president and saw Ukraine anchor its future with the West.
The Minsk talks are meant to end the diplomatic jousting by reinforcing two compromise September deals that preserve Ukraine as a single nation in which the Russian-border regions enjoy more self-rule.
Yet little of what was agreed nearly four months ago has been achieved.
The coal and steel producing regions of Lugansk and Donetsk staged their own leadership polls in November that infuriated Kiev and dampened early glimmers of hope of a political settlement being reached soon.
And insubordinate field commanders from both sides continued ignoring the formal truce declaration and waged battles that killed 1,300 more people.
UN officials fear that their total toll of 4,700 deaths may be too conservative because militias have been hiding their losses and denying outsiders access to their burial sites.
The most difficult task facing European mediators is finding a way for the sides to begin pulling back their tanks so that a 30-kilometre (18-mile) buffer zone could be established across the war zone.
The insurgents are currently most interested in seeing the resumption of social welfare payments that Kiev suspended last month out of fear that they were being used to finance the revolt.