Ukrainian military and separatist representatives exchanged dozens of prisoners under cover of darkness at a remote frontline location Saturday evening, kicking off a process intended to usher in peace to the conflict-ridden east. 139 Ukrainian troops and 52 rebels were exchanged, according to a separatist official overseeing the prisoner swap at a no man's land location near the village of Zholobok, some 20 kilometers (12 miles) west of the rebel-held city Luhansk.